J Microbiol Methods, 2005 Mar, 60(3), 325 - 33 Determination of an internal control to apply reverse transcription quantitative PCR to study stress response in the lactic acid bacterium Oenococcus oeni; Desroche N et al.; The expression gene pattern reflects, in part, mechanisms involved in adaptation to environmental conditions . Thus, we established and validated a method that enables relative transcript quantification in different conditions in the lactic acid bacteria Oenococcus oeni, notably in a technological medium . First, we determined an internal control in our conditions by reverse transcription quantitative polymerase chain reaction (RT-qPCR) using the SYBR(R) Green I technology . Among the seven presumed housekeeping tested genes, the ldhD gene was retained for further experiments . Then, the PCR reproducibility was verified in our conditions and the comparative critical threshold (2(DeltaDeltaC(T))) method was applied to quantify the transcript level of genes . The quantification of transcript levels of several stress genes already studied in our laboratory by Northern blot after a heat shock and at the entry of stationary phase allowed us to validate this method . RT-qPCR appeared as a powerful tool to study O . oeni response in stress conditions and wine mimetic conditions. Lett Appl Microbiol, 2005, 40(2), 99 - 105 Fate of Escherichia coli O157 and detection of stx phage during fermentation of maize, an animal feedstuff; Avery SM et al.; Abstract s.m . avery, l.d . walters and m.l . hutchison . 2004.Aims: The fate of inoculated Escherichia coli O157, stx phages and the physico-chemical properties of maize were studied during laboratory-scale fermentation by naturally occurring lactic acid bacteria . Methods and Results: Before fermentation, chopped maize was inoculated with 6.2 log(10) CFU g(-1) of a five-isolate mixture of E . coli O157 . After fermentation, the silage contained 70.6 g kg(-1) dry matter (DM) lactic acid and 12.8 g kg(-1) DM acetic acid and was pH 4.0 . Levels of E . coli O157 fell rapidly, and none of the five isolates could be recovered from the fermenting maize after 8 days . Using a resuscitation step did not consistently enhance recovery of E . coli O157 . Stx phages were not isolated from the fermenting maize at any time . Pulsed-field gel electrophoresis (PFGE) genotyping showed that E . coli O157 2975 and 64a/01 survived better than the other three isolates studied . Escherichia coli O157 isolate 1474/00 was particularly sensitive to the laboratory procedures used to harvest the inocula and contaminate the maize . Some colonies recovered during the fermentation had one to three band alterations compared with the initial PFGE genotypes . Significance and Impact of the Study: None of the five different E . coli O157 genotypes survived maize fermentation . Fermentation of maize produces an animal feedstuff that is unlikely to contain E . coli O157 or stx phages. Am J Transplant, 2005 Jan, 5(1), 125 - 30 Supply of pre- and probiotics reduces bacterial infection rates after liver transplantation-a randomized, double-blind trial; Rayes N et al.; Bacterial infections frequently occur early after liver transplantation . We recently reported significant progress with a synbiotic composition, consisting of one lactic acid bacteria (LAB) and one fiber, which reduced the infection rate from 48% (with selective bowel decontamination) to 13% . Now, our aim is to study if a combination of different LAB and fibers would further improve outcome . A prospective randomized double-blind trial was undertaken in 66 liver transplant recipients . All patients received enteral nutrition immediately post-operatively . Comparison was made between one group (A) receiving a composition of four LAB and four fibers and another group (B) receiving the fibers only . The treatment started the day before surgery and continued for 14 days . Thirty-day infection rate, length of hospital stay, duration of antibiotic therapy, non-infectious complications and side effects of enteral nutrition were recorded . The incidence of post-operative bacterial infections was significantly reduced; being 48% with only fibers and 3% with LAB and fibers . In addition, the duration of antibiotic therapy was significantly shorter in the latter group . In both groups, mainly mild or moderate infections occurred . Fibers and LAB were well tolerated . Early enteral nutrition supplemented with a mixture of LAB and fibers reduces bacterial infection rates following liver transplantation . Treatment with only fibers led to a low incidence of severe infections. Biochem Biophys Res Commun, 2005 Jan 28, 326(4), 782 - 7 Augmentation of T(H)-1 type response by immunoactive AT oligonucleotide from lactic acid bacteria via Toll-like receptor 9 signaling; Shimosato T et al.; Toll-like receptor 9, which is expressed on the surface of antigen presenting cells and which was recently identified in the cytoplasmic follicle, recognizes bacterial CpG oligodeoxynucleotides (ODNs), resulting in the induction of a potent immune response . However, in our previous study, we found that TLR9 potentially recognizes not only CpG ODN but also non-CpG ODN such as AT ODN . Therefore, in the present study, to investigate this possibility, we elucidated the effects of AT ODN on T(H)-1, T(H)-2 type cytokine induction via TLR9 by real-time quantitative PCR analysis and ELISA of the swine TLR9 transfectant . The results demonstrated that the T(H)-1 type cytokines such as interleukin (IL)-12p70 and interferon (IFN)-gamma were strongly induced by AT ODN compared to the unexposed controls, while T(H)-2 type cytokines were not induced . These results indicate that the AT ODN can augment the T(H)-1 immune response, which plays an important role in prevention of allergic responses . Moreover, the swine TLR9 transfectant demonstrated its usefulness for evaluation of immunostimulation by bacterial DNA through the detection of T(H)-1, T(H)-2 type cytokine induction via TLR9 signaling. Eksp Klin Gastroenterol, 2004, (4), 39 - 43, 109 {Immunostimulating and anti-carcinogenic activity of the normal intestinal lactoflora}; The possible role of natural idiotopes in immune memory; Institute of Immunology and Virology Torlak, Vojvode Stepe 458, 11152 Belgrade, Serbia and Montenegro . ljiljad@eunet.yu In this paper we report on the generation of Abs possessing specificities similar to those of Abs used in immunization, and on the generation of Id and anti-Id specificities in the sera of mice immunized with commensal bacterial antigens . The human monoclonal antibody IgM DJ (VH3/VL2) expresses natural antibody properties, natural idiotope (Y7), and specificity towards Lactic acid bacteria (LAB) . When used in immunization it generates LAB-specific antibodies . Immunization with LAB, as detected in the presence of biotin-labelled mouse monoclonal anti-idiotopic antibodies Y7 and IgM DJ generates Abs1 and Abs2, respectively . These findings may imply that the recognition of bacterial motifs accords with the rules of idiotypic network theory . This theory, first proposed by Jerne in 1974 and often overlooked since, has been subject to change during the course of immunological research . Recent experiments concerning the recognition of bacterial motifs and natural memory in the immune system have inspired us in our attempt at explaining the possible role of natural Id in immune memory. Prikl Biokhim Mikrobiol, 2004 Mar-Apr, 40(2), 210 - 3 {Antimicrobial activity of lactic acid bacteria from sour milk products "Narine", "Karine", and "Matsun"}; Martirosian AO et al.; We studied antimicrobial properties of lactic acid bacteria from sour milk products Narine, Karine, and Matsun . The whey of sour milk products included two major fractions of sugars and L-lactic acid and its sodium and calcium salts . Antimicrobial activity of Narine, Karine, and Matsun was related to the presence of L-lactic acid and its sodium and calcium salts. Expert Opin Biol Ther, 2004 Apr, 4(4), 439 - 41 Live genetically modified bacteria as drug delivery tools: at the doorstep of a new pharmacology? Steidler L. Recent advances in genetic modification technology show that lactic acid bacteria can constitutively produce functional, eukaryote-derived proteins without any apparent negative effect on bacterial growth and physiology . These bacteria appear capable of surviving and of being physiologically active at the mucosal surfaces of higher eukaryotes . Studies in animal models also suggest that these findings could have a major impact in human medicine . Alongside conceptual proofs, the development of a robust system for biological containment will allow for the examination of genetically modified lactic acid bacteria as vectors of therapeutic protein delivery in human healthcare. Eur J Biochem, 2004 May, 271(9), 1748 - 56 NMR solution structure of the precursor for carnobacteriocin B2, an antimicrobial peptide from Carnobacterium piscicola; Sprules T et al.; Type IIa bacteriocins, which are isolated from lactic acid bacteria that are useful for food preservation, are potent antimicrobial peptides with considerable potential as therapeutic agents for gastrointestinal infections in mammals . They are ribosomally synthesized as precursors with an N-terminal leader, typically 18-24 amino acid residues in length, which is cleaved during export from the producing cell . We have chemically synthesized the full precursor of carnobacteriocin B2, precarnobacteriocin (preCbnB2), which has a C-terminal amide rather than a carboxyl, and also produced preCbnB2(1-64), which is missing two amino acid residues at the C-terminus (Arg65 and Pro66), via expression in Escherichia coli as a maltose-binding protein fusion that is then cut with Factor Xa . PreCbnB2(1-64) is readily labeled with (15)N and (13)C for NMR studies using the latter approach . Multidimensional NMR analysis of preCbnB2(1-64) shows that, like the parent bacteriocin, it exists as a random coil in water but assumes a defined conformation in water/trifluoroethanol mixtures . In 70 : 30 trifluoroethanol/water, the 3D structure of the preCbnB2 section corresponding to the mature bacteriocin is essentially the same as reported previously by us for carnobacteriocin B2 (CbnB2) . This structure maintains the highly conserved alpha-helix corresponding to residues 20-38 of CbnB2 that is believed to be responsible for interaction with a target receptor in sensitive cells, including Listeria monocytogenes . PreCbnB2 also has a second alpha-helix from residues 3-13 (i.e . -15 to -5 relative to CbnB2) in the leader section of the peptide . This helix appears to be conserved in related type IIa bacteriocin precursors based on sequence analysis . It is likely to be a key recognition element for export and processing, and is probably responsible for the considerably reduced antimicrobial activity of preCbnB2 . The latter effect may assist the producing cell in avoiding the toxic effects of the bacteriocin . This is the first 3D structure determined for a prebacteriocin from lactic acid bacteria. Curr Opin Biotechnol, 2004 Apr, 15(2), 105 - 15 Genome data mining of lactic acid bacteria: the impact of bioinformatics; Siezen RJ et al.; Lactic acid bacteria (LAB) have been widely used in food fermentations and, more recently, as probiotics in health-promoting food products . Genome sequencing and functional genomics studies of a variety of LAB are now rapidly providing insights into their diversity and evolution and revealing the molecular basis for important traits such as flavor formation, sugar metabolism, stress response, adaptation and interactions . Bioinformatics plays a key role in handling, integrating and analyzing the flood of 'omics' data being generated . Reconstruction of metabolic potential using bioinformatics tools and databases, followed by targeted experimental verification and exploration of the metabolic and regulatory network properties, are the present challenges that should lead to improved exploitation of these versatile food bacteria. Curr Opin Biotechnol, 2004 Apr, 15(2), 100 - 4 Exploration of antimicrobial potential in LAB by genomics; Nes IF et al.; A tremendous flow of information has been created through various genome sequencing projects worldwide . So far, 128 bacterial genome sequences have been completed and 391 are under way . Many of these bacteria, including several lactic acid bacteria (LAB), are used in the production and preservation of food and feed . The major antimicrobial and biopreservative substance produced by LAB is organic acid; however, some LAB produce additional antimicrobial compounds . Among these, the bacteriocins have demonstrated great potential as food preservatives . Additionally, antimicrobial compounds different from the bacteriocins have recently been identified, of which several display strong antifungal activity . The information obtained from genomics and related technologies will have great impact on the future identification and development of new antimicrobial agents . Developments will include the identification of pathways for the production of antimicrobials and genome mining for new antimicrobial peptides. Curr Opin Biotechnol, 2004 Apr, 15(2), 86 - 93 Post-genomics of lactic acid bacteria and other food-grade bacteria to discover gut functionality; de Vos WM et al.; Recent years have seen an explosion in the number of complete or almost complete genomic sequences of lactic acid bacteria and other food-grade bacteria that are used in functional foods to increase the health of the consumer . These have been instrumental in the development of functional, comparative and other post-genomics approaches that provide the possibility to detect, unravel and understand their functionality in the human intestinal tract . In conjunction with other high-throughput approaches, these advances can be exploited in the functional food innovation cycle for developing new or designed probiotic and other bacterial products that impact gut health. J Appl Microbiol, 2004, 96(5), 1176 - 84 Methionine catabolism and production of volatile sulphur compounds by OEnococcus oeni; Pripis-Nicolau L et al.; AIMS: During malolactic fermentation (MLF), the secondary metabolisms of lactic acid bacteria (LAB) contribute to the organoleptic modification of wine . To understand the contribution of MLF, we evaluated the capacity of various wine LAB to metabolize methionine . METHODS AND RESULTS: Using gas chromatography (GC) coupled either with mass spectrometry (MS) or a flame photometry detector in sulphur mode (FPD), we studied this metabolism in laboratory media and wine . In laboratory media, several LAB isolated from wine were able to metabolize methionine . They formed methanethiol, dimethyl disulphide, 3-(methylsulphanyl)propan-1-ol and 3-(methylsulphanyl)propionic acid . These are known to have powerful characteristic odours and play a role in the aromatic complexity of wine . In various red wines, after MLF only the 3-(methylsulphanyl)propionic acid concentration increased significantly, as verified with several commercial starter cultures . This compound, which is characterized by chocolate and roasted odours, could contribute to the aromatic complexity produced by MLF . CONCLUSIONS: This study shows that LAB isolated from wine, especially OEnococcus oeni strains, the major species in MLF, are able to metabolize methionine to form volatile sulphur compounds . SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to demonstrate the capacity of wine LAB to metabolize methionine. J Food Prot, 2004 Mar, 67(3), 601 - 6 Sodium lactate addition on the quality and shelf life of refrigerated sliced poultry sausage packaged in air or nitrogen atmosphere; Cegielska-Radziejewska R et al.; The aim of this study was to determine the effect of sodium lactate addition on shelf-life extension of sliced poultry sausage packaged both in air and nitrogen atmospheres and stored in refrigerated conditions . Basic chemical composition, pH, and malonaldehyde content were assayed and color measurement using the reflection method was carried out . Microbiological examination consisted of determination of total number of aerobic psychrotrophic bacteria and number of lactic acid bacteria . Sensory evaluation of products was performed . Microbiological and sensory quality of sliced poultry meat sausage was dependent on the addition during production of sodium lactate and the composition of gases (air or nitrogen) used in packaging . Slices of poultry sausage with 1% as well as 2% of sodium lactate maintained their initial quality of evaluated sensory attributes longer, irrespective of the applied gases . Sodium lactate inhibited growth of aerobic psychrotrophic bacteria and lactic acid bacteria during refrigerated storage . Sodium lactate also inhibited the formation of malonaldehyde in sliced poultry sausage during refrigerated storage . The effectiveness of this process depended on the concentration of sodium lactate addition . It was concluded that 1% as well as 2% addition of sodium lactate could extend the shelf life of sliced poultry sausage packaged in air atmosphere and stored at 5 to 7 degrees C by 3 or 4 times, respectively . Sliced poultry sausage treated with 2% sodium lactate packed in nitrogen had the longest (35-day) shelf life . This was a sevenfold increase in the shelf life of sliced poultry sausage compared with the control. Pancreas, 2004 Mar, 28(2), 191 - 9 Effect of the antibacterial activity of pig pancreatic juice on human multiresistant bacteria; Kruszewska D et al.; INTRODUCTION: The role of the exocrine pancreas in regulating gut microflora colonization is unclear . The main objective in the current study was to assess the effect of pancreatic fluid on the growth of pathogenic bacteria and fungi . METHODS: The antibacterial activity of pure pig pancreatic juice collected from catheterized, healthy, conscious, and anesthetized pigs was investigated with multiresistant microbial isolates and nonpathogenic strains . Studies were performed on pathogenic bacterial and fungi as well as lactic acid bacteria and reference strains . RESULTS: Pancreatic juice was effective (P < 0.01) against multidrug resistant bacterial pathogens, whereas lactic acid bacteria were insensitive . The antibacterial action was independent of pancreatic juice proteolytic activity . The in vitro antibacterial properties of pancreatic juice last for several hours . Data suggest that broth composition may modulate the intensity of pancreatic juice antibacterial activity . CONCLUSIONS: Pancreatic juice antibacterial activity may be an important factor in limiting the colonization of pathogenic bacteria in the gastrointestinal tract . We postulate that observed antibacterial activity of the pancreatic juice could play an important role as one of the factors of innate immunity. Appl Environ Microbiol, 2004 Mar, 70(3), 1583 - 92 High-throughput metabolic fingerprinting of legume silage fermentations via Fourier transform infrared spectroscopy and chemometrics; Johnson HE et al.; Silage quality is typically assessed by the measurement of several individual parameters, including pH, lactic acid, acetic acid, bacterial numbers, and protein content . The objective of this study was to use a holistic metabolic fingerprinting approach, combining a high-throughput microtiter plate-based fermentation system with Fourier transform infrared (FT-IR) spectroscopy, to obtain a snapshot of the sample metabolome (typically low-molecular-weight compounds) at a given time . The aim was to study the dynamics of red clover or grass silage fermentations in response to various inoculants incorporating lactic acid bacteria (LAB) . The hyperspectral multivariate datasets generated by FT-IR spectroscopy are difficult to interpret visually, so chemometrics methods were used to deconvolute the data . Two-phase principal component-discriminant function analysis allowed discrimination between herbage types and different LAB inoculants and modeling of fermentation dynamics over time . Further analysis of FT-IR spectra by the use of genetic algorithms to identify the underlying biochemical differences between treatments revealed that the amide I and amide II regions (wavenumbers of 1,550 to 1,750 cm(-1)) of the spectra were most frequently selected (reflecting changes in proteins and free amino acids) in comparisons between control and inoculant-treated fermentations . This corresponds to the known importance of rapid fermentation for the efficient conservation of forage proteins. Int J Food Microbiol, 2004 Mar 1, 91(2), 109 - 17 Microbial and sensory quality of commercial fresh processed red lettuce throughout the production chain and shelf life; Allende A et al.; Red pigmented 'Lollo Rosso' lettuce was processed under usual and controlled conditions in an industrial plant . At different steps of the production chain (reception, shredding, washing, draining, rinsing, centrifugation, and packaging), microbial counts were evaluated . Following industrial practices, processed lettuce was packaged at 5 degrees C in sealed polypropylene (PP) bags with an initial atmosphere containing 3 kPa O(2) and 5 kPa CO(2) . The numbers of psychrotrophic bacteria, coliform and lactic acid bacteria (LAB) were influenced by all the studied steps of the production chain of the fresh processed 'Lollo Rosso' lettuce . Shredding, rinsing and centrifugation in particular increased bacterial counts . During a storage period of 7 days at 5 degrees C, sensory attributes (general appearance, texture, aroma, translucency, initial and persistent off-odors, leaves superficial browning, leaves edges browning, and decay) as well as microbial counts (psychrotrophic and mesophilic bacteria, coliforms and lactic acid bacteria) were monitored . Due to high microbial counts and off-odors evaluation, a shelf life shorter than 7 days should be considered for fresh processed 'Lollo Rosso' lettuce. FEMS Immunol Med Microbiol, 2004 Mar 8, 40(2), 119 - 27 Development and validation of a new in vitro assay for selection of probiotic bacteria that express immune-stimulating properties in chickens in vivo; Koenen ME et al.; Oral administration of immunoprobiotic bacteria may support animal health . Species specificity of such microorganisms requires appropriate selection . An in vitro assay for the selection of immunoprobiotic lactic acid bacteria was developed in chicken . The assay allowed testing of large numbers of individual strains . Immune stimulation in vitro correlated well with the in vivo situation in two experiments and no false negative results occurred . Therefore this assay is an appropriate selection tool for immunomodulating properties of lactic acid bacteria in chicken. J Biomater Sci Polym Ed, 2003, 14(11), 1269 - 81 Survival of lactic acid bacteria in simulated gastrointestinal juice protected by a DNA-based complex gel; Jonganurakkun B et al.; Salmon milt DNA was utilized in the approach to protect functional materials, proteins, microorganisms, drugs, etc., by forming a DNA-based complex gel with gelatin and kappa-carrageenan . The multiplier effect of the combination of DNA, gelatin and kappa-carrageenan was examined by measuring the release of methyl orange from the gel after being incubated in simulated gastric juice . The results indicated that the hydrogel made of DNA, gelatin and kappa-carrageenan can efficiently maintain the functional materials . Furthermore, a complex gel was developed and optimized by applying an emulsion of lactic acid bacteria and cacao oil onto the already prepared hydrogel . The existence of the lactic acid bacteria in the oil emulsion particles was confirmed by scanning electron microscopy . The protection capabilities in the simulated gastrointestinal juice, which had a viability of 1.50 x 10(6) CFU/g gel after 2 h incubation in the simulated gastric juice and 2.53 x 10(7) CFU/g gel after 6 h continued incubation in the simulated intestinal juice, were measured, in contrast to 2.58 x 10(7) CPU/g in the original gel before treatment. Curr Microbiol, 2003 Dec, 47(6), 508 - 13 Survival of lactic acid bacteria in seawater: a factorial study; Vazquez JA et al.; A feasibility study of lactic bacteria as potential probiotics in larval cultures of marine fish was performed by investigating the survival of five strains of lactic bacteria in seawater by readily standardized procedures at different temperatures and salinities . These conditions were chosen in such a way that their combinations define a complete first-order factorial design . Depending on the strain and the ambient conditions, the survival adhered to first-order kinetics in some cases, and to the Gompertz equation in others . The half lives (t0.5) calculated from these models were subsequently introduced as responses to the factorial designs, estimating the coefficients of empirical equations that describe the group effect of temperature and salinity on t0.5 . Simply additive effects were found in two cases, a negative first-order interaction in another case, while another two required second-order models. J Nutr Health Aging, 2004, 8(1), 20 - 5 The effect of aging on mucosal host defense; Cunningham-Rundles S; Mucosal immune response is primed at birth and responses generated at this time support specific immunity in later life . Conversely development of mucosal immune response to new antigens is diminished in aging . Availability of key nutrients that are conditionally essential especially in the context of sub-acute infections may limit immune response . A critical hypothesis is that conditionally essential nutrient requirements are associated with aging and form the fundamental basis of observed immune senescence . Since mucosal immunity is modulated by the interaction of microflora with the gut immune system, it is likely that changes in the gut during aging affect this microenvironment . Probiotic lactic acid bacteria offer one approach to stimulating the gastrointestinal immune system thereby enhancing systemic as well as mucosal immune response in aging . The mechanisms of action appear to include specific stimulation of natural killer cells (NK) and the innate immune system. J Appl Microbiol, 2004, 96(1), 133 - 43 The contribution of bacteriocin to inhibition of Listeria monocytogenes by Carnobacterium piscicola strains in cold-smoked salmon systems; Nilsson L et al.; AIMS: To study the importance of bacteriocin production for the antilisterial effect of a bacteriocinogenic Carnobacterium piscicola strain A9b on growth of Listeria monocytogenes in broth and cold-smoked salmon systems . METHODS AND RESULTS: Acriflavin treatment of strain A9b resulted in loss of bacteriocin production and of immunity to carnobacteriocin B2 . Two plasmids present in the wild-type were lost in the variant that was also more sensitive to bavaricin and leucocin A than the wild-type indicating cross-resistance to class IIa bacteriocins . The growth rate of the bac- mutant was higher than that of the wild-type at 5 and 37 degrees C but not at 25 or 30 degrees C . In salmon juice the maximum cell density of L . monocytogenes was suppressed 3 and 6 log by co-culture with C . piscicola A9b bac- and bac+, respectively, as compared with the control . Sterile filtered cultures of C . piscicola A9b bac- caused a limited suppression of the maximum cell density of L . monocytogenes similar to that observed when sterile buffer was added in equal amounts . Semi-purified carnobacteriocin B2 caused a 3.5 log decline in viable cell count after 6 day of incubation in cold-smoked salmon juice at 5 degrees C . High resistance level to carnobacteriocin B2 was observed for L . monocytogenes cells exposed to semi-purified and in situ produced carnobacteriocin B2 . CONCLUSIONS: The presence of bacteriocin production in C . piscicola enhances its inhibition of L . monocytogenes . SIGNIFICANCE AND IMPACT OF THE STUDY: Due to the emergence of resistance, a bacteriocin negative lactic acid bacteria may be more suited for practical use as a bioprotective agent against L . monocytogenes in ready-to-eat foods. Acta Vet Scand, 2003, 44(1-2), 73 - 86 Survival of Listeria monocytogenes in wilted and additive-treated grass silage; Pauly TM et al.; Grass was field-dried to 3 different dry matter (DM) levels (200, 430 and 540 g/kg) and inoculated with 10(6)-10(7) cfu/g of a Listeria monocytogenes strain sharing a phagovar occasionally involved in foodborne outbreaks of listeriosis . Formic acid (3 ml/kg) or lactic acid bacteria (8 x 10(5)/g) with cellulolytic enzymes were applied only to forages with low and intermediate DM levels . Forages were ensiled in laboratory silos (1700 ml) and were stored at 25 degrees C for 30 or 90 days . After 90 days of storage, L . monocytogenes could not be detected in any silo, except one with the high dry matter grass without additive . After 30 days of storage, between 10(2) and 10(6) cfu L . monocytogenes/g silage were isolated from the untreated silages . Increasing the DM content from 200 to 540 g/kg did not reduce listeria counts possibly because of the lower production of fermentation acids (higher pH) . In silages treated with additives, counts of L . monocytogenes were always lower than in silages without additive . In wet silages (DM 200 g/kg) both additives were effective, but in the wilted silages (DM 430 g/kg) only the bacterial additive reduced listeria counts below detection level . Listeria counts were highly correlated to silage pH (r = 0.92), the concentration of lactic acid (r = -0.80) and the pooled amount of undissociated acids (r = -0.83). Vet Microbiol, 2003 Dec 2, 97(1-2), 55 - 61 Absence of host specificity for in vitro adhesion of probiotic lactic acid bacteria to intestinal mucus; Rinkinen M et al.; Adhesion of probiotic lactic acid bacteria (LAB) has been reported to be host species specific . Host specificity is regarded as a desirable property for probiotic bacteria and therefore recommended as one of the selection criteria . However, previous studies have indicated that LAB originating from one host adhere well also to the mucus of other species . The aim of the study was to investigate the host specificity of LAB adhesion in human, canine, possum, bird and fish mucus in vitro . An in vitro mucus adhesion model was utilized in this study using immobilized mucus from faeces or intestinal material of these hosts . The results indicate that the adhesion trait was not host specific but rather was characteristic to LAB species . In conclusion, mucus adhesion properties are more dependent on the LAB strain than on the host . This suggests that animal models in probiotic adhesion assays may be more applicable to other species than thought earlier . Positive health effects facilitated by adherent probiotics in humans may also denote the possibility of similar outcome in other species and vice versa. J Food Prot, 2003 Nov, 66(11), 2085 - 92 Microbiological and physicochemical properties of fresh retail cuts of beef packaged under an advanced vacuum skin system and stored at 4 degrees C; Barros-Velazquez J et al.; The effect of an advanced vacuum skin packaging system on the microbiological and physicochemical properties of fresh retail cuts of beef (including meat portions from six different anatomical regions) stored at 4 degrees C was compared with the effect of traditional vacuum packaging . The vacuum skin packaging system whose effect on meat quality was evaluated in this work displayed two remarkable features: (i) the instantaneous heating of the lower surface of the upper film of the package before the film descended over the meat surface and (ii) the tight disposition of the plastic film on the meat surface, which avoided wrinkles and purges . Throughout storage at 4 degrees C, rates of bacterial growth were statistically significantly slower in beef portions processed with the vacuum skin packaging system than in those processed with traditional vacuum packaging, with average differences of 2.07, 1.60, and 1.25 log CFU/g in counts of aerobic mesophiles, anaerobes, and lactic acid bacteria, respectively . pH values were statistically significantly lower for beef portions packaged with the vacuum skin system than for those that were vacuum packaged in the traditional manner, probably because of the relative predominance of lactic acid bacteria observed in such samples, which coincided with both higher meat firmness values and a slower meat tenderization process . The vacuum skin system prevented the appearance of undesirable coloration on the meat surface and also significantly improved the commercial color of the meat as determined on the basis of luminosity (L*) and the redness (a*) . Overall, the quality (as determined by microbiological and physicochemical analyses and by visual examination) of fresh retail cuts of beef packaged with the vacuum skin system and stored at 4 degrees C was higher than that of meat samples processed with the traditional vacuum-packaging system. Langenbecks Arch Surg, 2004 Apr, 389(2), 145 - 54 Epub 2003 Nov 07. Bio-ecological control of perioperative and ITU morbidity; Bengmark S; BACKGROUND: Perioperative and intensive therapy unit (ITU) morbidity and mortality has remained unchanged during the past several decades, and this at an unacceptably high level . It is most likely, in the EU countries annually, that more than 1 million people suffer severe sepsis and some 300,000 die . Pharmaceutical attempts at prevention and treatment have, despite extensive efforts, hitherto failed to improve outcome more significantly . Much supports the fact that sepsis and its severe consequences are results of a malfunctioning innate immune system, impaired by both lifestyle and disease . A series of mostly simple measures to prevent further deterioration of the immune system, and to boost it, is recommended . Among the measures recommended are some modifications of surgical and postoperative management: restricted use of antibiotics, attempts made to maintain salivation and GI secretions, omission of prophylactic gastric decompression, postoperative drainage and preoperative bowel preparation, restricted use of stored blood, avoidance of overload with nutrients, uninterrupted enteral nutrition but also tight blood glucose control, supply of antioxidants, administration of prebiotic fibre and probiotic lactic acid bacteria . Nutritional control of postoperative morbidity includes use of so-called synbiotics, e.g . a combination of bioactive lactic acid bacteria (LAB) and bioactive plant fibres . RESULTS: Dramatic reduction in (in reality, almost abolishment of) septic morbidity is reported following supplementation of specific bioactive lactic bacteria in combination with prebiotic plant fibres, as tried in controlled studies in connection with extensive abdominal operations, liver transplantation and severe acute pancreatitis. Appl Environ Microbiol, 2003 Nov, 69(11), 6801 - 7 Design and evaluation of PCR primers for analysis of bacterial populations in wine by denaturing gradient gel electrophoresis; Lopez I et al.; Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified ribosomal DNA (rDNA) is routinely used to compare levels of diversity of microbial communities and to monitor population dynamics . While using PCR-DGGE to examine the bacteria in wine fermentations, we noted that several commonly used PCR primers for amplifying bacterial 16S rDNA also coamplified yeast, fungal, or plant DNA present in samples . Unfortunately, amplification of nonbacterial DNA can result in a masking of bacterial populations in DGGE profiles . To surmount this problem, we developed two new primer sets for specific amplification of bacterial 16S rDNA in wine fermentation samples without amplification of eukaryotic DNA . One primer set, termed WLAB1 and WLAB2, amplified lactic acid bacteria, while another, termed WBAC1 and WBAC2, amplified both lactic acid bacterial and acetic acid bacterial populations found in wine . Primer specificity and efficacy were examined with DNA isolated from numerous bacterial, yeast, and fungal species commonly found in wine and must samples . Importantly, both primer sets effectively distinguished bacterial species in wine containing mixtures of yeast and bacteria. Int J Food Microbiol, 2003 Dec 1, 88(2-3), 235 - 40 Enterococcus faecium RZS C5, an interesting bacteriocin producer to be used as a co-culture in food fermentation; Leroy F et al.; Enterocins, bacteriocins produced by enterococci, are gaining interest because of their industrial potential . Due to its bacteriocin production, Enterococcus faecium RZS C5, a natural cheese isolate, has a strong activity towards Listeria monocytogenes . For this reason, the strain may be applicable as a bacteriocin-producing co-culture in food fermentation in order to reduce the risk on Listeria outgrowth . The strain displays remarkable bacteriocin production kinetics . Whereas most lactic acid bacteria produce bacteriocin in a growth-associated way until the beginning of the stationary phase, bacteriocin production by E . faecium RZS C5 in MRS broth at controlled pH values below 7.5 is characterised by a boost of bacteriocin activity levels in the very early growth phase . In addition, bacteriocin production kinetics are closely linked to the environmental and cultural conditions . However, no straightforward statement about the effect of environmental stress on bacteriocin production can be made since the effect is dependent on the type of stress applied . Kinetic experiments in milk and on pilot scale, applying Cheddar cheese-making conditions, have indicated that the strain may be effective as a bacteriocin-producing co-culture . Further research is needed to evaluate the use of E . faecium RZS C5 as a co-culture for the production of fermented sausage. Int J Food Microbiol, 2003 Dec 1, 88(2-3), 223 - 33 Functionality of enterococci in meat products; Hugas M et al.; The presence of enterococci in meat fermentation is a constant as reported in the literature . Despite the concern about pathogenicity of enterococci, recent studies point out that food and meat enterococci, especially Enterococcus faecium have a much lower pathogenicity potential than clinical strains . Enterococci possess a competitive advantage over other microbiota in meat fermentations, and many enterococci isolated from sausages have the ability to produce enterocins harbouring antimicrobial activity against pathogens and spoilage microorganisms of meat concern . The application of enterocins producing enterococci or their purified metabolites, as extra hurdles for preservation in sausage fermentation and in sliced-vacuum packed cooked meat products can be beneficial, preventing the outgrowth of Listeria monocytogenes and slime-producing lactic acid bacteria . Enterocins and bacteriocinogenic enterococci hold considerable promise as alternatives to traditional chemical preservatives and they could be exploited for the control of emergent pathogens in meat products . Their inhibitory effect can be increased when used in conjunction with particular physical and chemical processes, but current regulation is hampering the application of purified bacteriocins. Int J Food Microbiol, 2003 Dec 15, 89(1), 85 - 90 Improvement of organoleptic quality of retted cassava products by alkali pretreatment of roots and addition of sodium nitrate during retting; Ogbo FC; Alkali pretreatment of cassava roots before retting and addition of sodium nitrate during retting were used to manipulate the metabolism of microorganisms involved in cassava (Manihot esculenta Crantz) retting, as a method for removing the characteristic offensive odour of retted cassava products . Odour was assessed by organoleptic methods . The characteristics of fermentation of cassava by the traditional method (control) were as follows; aerobic mesophilic count (APC) on nutrient agar (NA) at 30 degrees C/48 h, attained a maximum of 2.3 x 10(7)/ml retting juice while counts on de Man Rogosa and Sharpe agar (MRS) at 30 degrees C/48 h were 1.6 x 10(8)/ml . Maximum titrable acidity was 0.062% lactic acid by weight of retting juice . Cassava was retted in 3 days and the product exhibited characteristic offensive odour . Addition of NaNO3 into retting water effectively removed odour at a concentration of 0.3 g/l . Maximum APC on NA/30 degrees C/48 h was 6.8 x 10(6)/ml . Counts on MRS/30 degrees C/48 h exceeded 2.4 x 10(9)/ml . Retting was complete in 3 days with a final titrable acidity of 0.068% of retting juice . Removal of odour likely resulted from selection of homo-fermentative lactic acid bacteria, thus producing mostly odourless lactic acid . Alkali pretreatment of roots before retting was efficacious in removing odour at a concentration of 10 g/l for 30 min . This fermentation was characterized by APC on NA/30 degrees C/48 h of 5.4 x 10(6)/ml; MRS/30 degrees C/48 h reached a maximum of only 10 x 10(4)/ml and correspondingly low titrable acidity of 0.003% . Low counts of lactic acid bacteria correlate well with the absence of odour in this sample . Both treatments did not adversely affect the detoxification process, yielding "foo-foo" with HCN levels lower than 10 mg/kg . Residual nitrates and nitrites of 30 mg/kg in the sodium nitrate-treated sample were also within the safe limits of 156 mg/kg allowed in many countries . Organoleptically improved samples were acceptable to the public. Trends Biotechnol, 2003 Nov, 21(11), 491 - 7 Genetically modified probiotics in foods; Ahmed FE; Probiotics have many potential therapeutic uses, but have not been universally accepted because of a lack of understanding of their action . Lactic acid bacteria (LAB) have been modified by traditional and genetic engineering methods to produce new varieties . Modern techniques of molecular biology have facilitated the identification of probiotic LAB strains, but only a few LAB have been modified by recombinant-DNA technology because of consumer resistance to their introduction to markets, especially in Europe. Biotechnol Adv, 2001 Dec, 19(8), 597 - 625 Biosynthesis, characterisation, and design of bacterial exopolysaccharides from lactic acid bacteria; Laws A et al.; Lactic acid bacteria (LAB) are characterised by their conversion of a large proportion of their carbon feed, fermentable sugars, to lactic acid . However, in addition to lactic acid production, the LAB are able to divert a small proportion of fermentable sugars towards the biosynthesis of exopolysaccharides (EPSs) that are independent of the cell surface and cell wall material . These microbial EPSs when suspended or dissolved in aqueous solution provide thickening and gelling properties, and, as such, there is great interest in using EPSs from food grade microorganisms (such as the LAB that are traditionally used for food fermentations) for use as thickening agents . The current review includes a brief summary of the recent literature describing features of the biosynthetic pathways leading to EPS production . Many aspects of EPS biosynthesis in LAB are still not fully understood and a number of inferences are made regarding the similarity of the pathway to those involved in the synthesis of other cell polysaccharides, e.g., cell wall components . The main body of the review will cover practical aspects concerned with the isolation and characterisation of EPS structures . In the last couple of years, a substantial number of structures have been published and a summary of the common elements of these structures is included as is a suggestion for a system for representing structures . A brief highlight of the attempts that are being made to design 'tailor'-made polysaccharides using genetic modification and control of metabolic flux is presented. Biotechnol Adv, 1998 May, 16(3), 581 - 608 Probiotics: functionality and commercial status; Scheinbach S; Probiotics in the form of fermented milk products have been consumed for centuries . In this century various health benefits have been purported to result from consumption of foods containing live microorganisms, particularly lactic acid bacteria (LAB) . Probiotics can provide relief for lactose intolerant individuals and reduce bouts of diarrhea . Evidence for other claims such as lowering serum cholesterol, suppressing cancer and stimulating the immune system remains to be clearly established by conducting well-controlled, statistically-valid clinical trials . Although the benefits to healthy individuals are uncertain, many consumers especially in Japan and Europe, perceive probiotic products to be healthful, and sales are robust. Int J Food Microbiol, 2003 Nov 15, 88(1), 19 - 28 Utilization of various starter cultures in the production of Amasi, a Zimbabwean naturally fermented raw milk product; Gran HM et al.; Fermented milk was prepared from unpasteurised milk using natural fermentation (R), back-slopping (B) and by addition of two different starter cultures (C1 and DL) . The numbers of Escherichia coli, coliforms, lactic acid bacteria (LAB) and the changes in pH, carbohydrates, organic acids and volatile compounds were recorded during 48-h fermentation . After 48-h fermentation, the highest numbers of E . coli were found in R and B fermentations and the lowest in the DL fermentation . The DL culture reduced the pH faster than the other starter cultures . The DL and C1 had higher levels of LAB in the beginning of the fermentation than the other two . Galactose and lactic acid increased fastest in the DL and C1 fermentation, and R was slowest . The highest levels of succinate, ethanol and malty compounds were found in the R and B fermentations . Lower levels of LAB in the first part of the fermentations, but higher number of E . coli could explain the increased levels of succinate, ethanol and malty compounds. Best Pract Res Clin Gastroenterol, 2003 Oct, 17(5), 849 - 59 Probiotics and colon cancer; Rafter J; Although a myriad of health-promoting effects have been attributed to the probiotic lactic acid bacteria, perhaps the most interesting and controversial is that of anticancer activity, the vast majority of studies in this area dealing with protective effects against colon cancer.There is no direct experimental evidence for cancer suppression in humans as a result of the consumption of probiotic cultures in fermented or unfermented dairy products, but there is a wealth of indirect evidence, based largely on laboratory studies . Reports in the literature regarding the anticancer effects of lactic acid bacteria fall into the categories of in vitro studies, animal studies, epidemiological studies and human dietary intervention studies . Examples of these reports will be given in the current paper . The mechanisms by which probiotic bacteria may inhibit colon cancer are still poorly understood, but, several potential mechanisms are being discussed in the literature, and these will also be addressed in this review. Mol Microbiol, 2003 Oct, 50(1), 303 - 17 Genome and proteome of Listeria monocytogenes phage PSA: an unusual case for programmed + 1 translational frameshifting in structural protein synthesis; Zimmer M et al.; PSA is a temperate phage isolated from Listeria monocytogenes strain Scott A . We report its complete nucleotide sequence, which consists of a linear 37 618 bp DNA featuring invariable, 3'-protruding single stranded (cohesive) ends of 10 nucleotides . The physical characteristics were confirmed by partial denaturation mapping and electron microscopy of DNA molecules . Fifty-seven open reading frames were identified on the PSA genome, which are apparently organized into three major transcriptional units, in a life cycle-specific order . Functional assignments could be made to 33 gene products, including structural proteins, lysis components, DNA packaging proteins, lysogeny control functions and replication proteins . Bioinformatics demonstrated relatedness of PSA to phages infecting lactic acid bacteria and other low G + C Gram-positives, but revealed only few similarities to Listeria phage A118 . Virion proteins were analysed by amino acid sequencing and mass spectrometry, which enabled identification of major capsid and tail proteins, a tape measure and a putative portal . These analyses also revealed an unusual form of translational frameshifting, which occurs during decoding of the mRNAs specifying the two major structural proteins . Frameshifting yields different length forms of Cps (gp5) and Tsh (gp10), featuring identical N-termini but different C-termini . Matrix-assisted laser-desorption ionization mass spectrometry (MALDI-MS) and electrospray ionization mass spectrometry (ESI-MS) of tryptic peptide fragments was used to identify the modified C-termini of the longer protein species, by demonstration of specific sequences resulting from + 1 programmed translational frameshifting . A slippery sequence with overlapping proline codons near the 3' ends of both genes apparently redirects the ribosomes and initiates the recoding event . Two different cis-acting factors, a shifty stop and a pseudoknot, presumably stimulate frameshifting efficiency . PSA represents the first case of + 1 frameshifting among dsDNA phages, and appears to be the first example of a virus utilizing a 3' pseudoknot to stimulate such an event. J Food Prot, 2003 Sep, 66(9), 1631 - 6 Synergy between nisin and select lactates against Listeria monocytogenes is due to the metal cations; McEntire JC et al.; Listeria monocytogenes, a major foodborne pathogen, has been responsible for many outbreaks and recalls . Organic acids and antimicrobial peptides (bacteriocins) such as nisin are produced by lactic acid bacteria and are commercially used to control pathogens in some foods . This study examined the effects of lactic acid (LA) and its salts in combination with a commercial nisin preparation on the growth of L . monocytogenes Scott A and its nisin-resistant mutant . Because of an increase in its activity at a lower pH, nisin was more active against L . monocytogenes when used in combination with LA . Most of the salts of LA, including potassium lactate, at up to 5% partially inhibited the growth of L . monocytogenes and had no synergy with nisin . Zinc and aluminum lactate, as well as zinc and aluminum chloride (0.1%), worked synergistically with 100 IU of nisin per ml to control the growth of L . monocytogenes Scott A . No synergy was observed when zinc or aluminum lactate was used with nisin against nisin-resistant L . monocytogenes . The nisin-resistant strain was more sensitive to Zn lactate than was wild-type L . monocytogenes Scott A; however, the cellular ATP levels of the nisin-resistant strain were not significantly affected . Changes in the intracellular ATP levels of the wild-type strain support our hypothesis that pretreatment with zinc lactate sensitizes cells to nisin . The similar effects of thesalts of hydrochloric and lactic acids support the hypothesis that metal cations are responsible for synergy with nisin. Microbiology, 2003 Aug, 149(Pt 8), 2227 - 34 Cloning and functional expression of dipeptidyl peptidase IV from the ruminal bacterium Prevotella albensis M384(T); Walker ND et al.; Ruminal bacteria of the genus Prevotella play a crucial role in peptide breakdown in the rumen, a component of protein catabolism that leads to the inefficient use of dietary protein by ruminant animals . This is the first report of the cloning of a peptidase gene from a ruminal bacterium . Part of the dipeptidyl peptidase type IV (DPP-IV) gene from Prevotella albensis M384(T) was cloned using degenerate primers designed from conserved regions found within other known DPP-IV sequences . Flanking regions were determined by genomic walking . The DPP-IV gene was expressed in Escherichia coli . The cloned enzyme required a free N terminus and catalysed the removal of X-Pro dipeptide from proline-containing oligopeptides, where proline was the second residue from the N terminus . It was inhibited by serine protease inhibitors and the substrate analogue for mammalian DPP-IV, diprotin A . The properties of the cloned enzyme were similar to those of the native form in P . albensis and, in general, DPP-IVs from other organisms . The enzyme contained a conserved motif which is associated with the S9 class of prolyl oligopeptidases . The DPP-IV gene appeared not to be part of a contiguous operon . Regions with similarity to other putative promoters of Prevotella spp . were also identified . Construction of a phylogenetic tree demonstrated that the DPP-IV of P . albensis clusters with other DPP-IVs found in bacteria of the Cytophaga-Flexibacter-Bacteroidaceae (CFB) phylum, which are more closely related to eukaryotic DPP-IVs than the DPP-IV-like enzyme (PepX) of the lactic acid bacteria. J Agric Food Chem, 2003 Aug 13, 51(17), 5073 - 8 Hydrolysis of wine aroma precursors during malolactic fermentation with four commercial starter cultures of Oenococcus oeni; Ugliano M et al.; The ability of four commercial preparations of Oenococcus oeni lactic acid bacteria (EQ 54, Lalvin OSU, Uvaferm Alpha, and Lalvin 31) to hydrolyze wine aroma precursors was evaluated by measuring the concentration of free and bound aroma compounds at the end of malolactic fermentation carried out in model wines containing a mixture of glycosides extracted from Muscat wine . At pH 3.4 there was a decrease in glycosylated compounds matched by a concomitant increase in free forms in all starter cultures tested . When malolactic fermentation was carried out at pH 3.2, a significant decrease in the ability to hydrolyze aroma precursors was observed for two of the cultures tested (Uvaferm Alpha and Lalvin 31) . Large differences in the extent of hydrolysis and in the specificity of this activity toward specific aroma precursors were observed and appeared to be related to the chemical structure of the aglycon as well as to individual characteristics of each starter culture . The amounts of glycosylated aroma compounds released during malolactic fermentation suggest that O . oeni can alter the sensory characteristics of wine through the hydrolysis of aroma precursors. FEMS Microbiol Lett, 2003 Aug 8, 225(1), 115 - 23 Development of specific fluorescent oligonucleotide probes for in situ identification of wine lactic acid bacteria; Blasco L et al.; A rapid method for the identification of lactic acid bacteria (LAB) from wine has been developed . This method is based on fluorescence in situ hybridisation (FISH), using fluorescent oligonucleotide probes, homologous to 16S rDNA of those species of LAB commonly found in wines . The protocol for the specific detection of these bacteria was established through the hybridisation of 36 reference strains . The specificity of the probes was evaluated by using pure cultures . Probes were used to identify species in different wines, making it evident that direct identification and quantification from natural samples without culturing is also possible . The results show that FISH is a promising technique for the rapid identification of LAB, allowing positive identification in a few hours (4-16 h). Int J Food Microbiol, 2003 Sep 1, 86(1-2), 131 - 40 Yeasts as adjunct starters in matured Cheddar cheese; Ferreira AD et al.; Debaryomyces hansenii and Yarrowia lipolytica are typical foodborne yeast species frequently associated with dairy products and capable of predominating the yeast composition in such systems . The two species fulfil a number of criteria to be regarded as co-starters for cheesemaking . They are known for their proteolytic and lipolytic activity as well as their compatibility and stimulating action with the lactic acid starter cultures when co-inoculated . Recent studies indicated that yeasts could be included as part of starter cultures for the manufacturing of cheese, enhancing flavour development during the maturation . The potential of D . hansenii and Y . lipolytica as agents for accelerated ripening of matured Cheddar cheese has been evaluated during four cheese treatments . The interaction between the two yeast species and the lactic acid bacteria was surveyed incorporating (i) D . hansenii, (ii) Y . lipolytica, (iii) both species as adjuncts to the starter culture and (iv) a control cheese without any additions for the production of matured Cheddar cheese . The physical and chemical properties of the cheeses were monitored in order to evaluate the contribution of the yeasts to cheese maturation . The yeasts grew in association with the lactic acid bacteria without any inhibition . The yeasts species when individually added contributed to the development of bitter flavours despite accelerated development of strong Cheddar flavours . When both species were incorporated as part of the starter culture, the cheese, however, had a good strong flavour after a reduced ripening period . The cheese retained this good flavour and aroma after 9 months of production . The simultaneous application of D . hansenii and Y . lipolytica as part of the starter culture for the production of matured Cheddar cheese is proposed. Int J Food Microbiol, 2003 Sep 1, 86(1-2), 51 - 60 The role of interaction between yeasts and lactic acid bacteria in African fermented milks: a review; Narvhus JA et al.; Yeasts are present in indigenous African fermented milks in numbers up to log 8 cfu g(-1), together with a varied lactic acid bacteria (LAB) flora, and therefore potentially contribute to product characteristics . However, interaction between yeasts and LAB in these products has received little notice . In studies of indigenous fermented milk in Zimbabwe and Uganda, many samples contained more than one species of yeast, but Saccharomyces cerevisiae was most commonly isolated . Other frequent isolates were other species of Saccharomyces and several species of Candida . Most yeast isolates were lactose-negative but usually galactose-positive . Some strains assimilated lactate and citrate . The growth in milk of strains of yeasts and LAB, isolated from naturally soured milk in Zimbabwe, and their interaction when selected pairs of strains were grown together has been studied . Interactions were shown by the significantly different amounts of certain metabolites produced, such as acetaldehyde and malty aldehydes, when co-cultures were compared to pure cultures . Preliminary sensory acceptance tests did not show, however, that milks made from a co-culture with Candida kefyr and LAB were preferable to the pure LAB culture . Further work is still needed to elucidate the reactions that may be taking place in fermented milk between varying LAB and yeast populations . The potential for use as starter cultures depends on various aspects, including the final product being prepared . The role of other microorganisms in naturally fermented milk also needs to be studied. J Appl Microbiol, 2003, 95(2), 344 - 53 Typification of Oenococcus oeni strains by multiplex RAPD-PCR and study of population dynamics during malolactic fermentation; Reguant C et al.; AIMS: The goal of this study was to develop a reproducible method for molecular typing strains of Oenococcus oeni, and also to apply it in the study of population dynamics of these strains during malolactic fermentation of wine . METHODS AND RESULTS: A new method of multiplex randomly amplified polymorphic DNA (RAPD)-PCR has been developed, based on the combination of one random 10-mer and one specific 23-mer oligonucleotide in a single PCR . This method generates unique and discriminant DNA profiles for strains of O . oeni . The strains of this species were also clearly distinguished from other species of lactic acid bacteria . The method was applied to study the dynamics of O . oeni strains during malolactic fermentation, in three vintages in the same cellar . CONCLUSIONS: A fast and reliable method for typing strains of O . oeni has been designed and optimized . It improves the reproducibility and rapidity of conventional RAPD-PCR, and it has been validated monitoring the population dynamics during malolactic fermentation . SIGNIFICANCE AND IMPACT OF THE STUDY: This method will be a good tool to study the population dynamics of bacteria during malolactic fermentation and to evaluate the performance of new malolactic starter cultures and their dominance over the native microbiota. Antibiot Khimioter, 2003, 48(2), 13 - 5 {Antagonistic activity of lactic acid bacteria against pathogens localized outside the gastrointestinal tract}; Gavrilova NN et al.; Our research has proved that lactic acid bacteria possess the wide spectrum of antimicrobial activity . They inhibit the growth of not only agents of intestinal infections but also diseases located outside the gastrointestinal tract. Trends Biotechnol, 2003 Jun, 21(6), 269 - 74 Exopolysaccharides from lactic acid bacteria: perspectives and challenges; Welman AD et al.; Some lactic acid bacteria (LAB) secrete a polysaccharide polymer . This extracellular polysaccharide, or "exopolysaccharide" (EPS), is economically important because it can impart functional effects to foods and confer beneficial health effects . LAB have a "Generally Recognized As Safe" (GRAS) classification and are likely candidates for the production of functional EPSs . Current challenges are to improve the productivity of EPSs from LAB and to produce EPSs of a structure and size that impart the desired functionality . The engineering of improvements in these properties will depend on a deep understanding of the EPS biosynthetic metabolism and of how the structure of EPSs relates to a functional effect when incorporated into a food matrix. J Dairy Sci, 2003 May, 86(5), 1608 - 15 Effects of standardization of whole milk with dry milk protein concentrate on the yield and ripening of reduced-fat cheddar cheese; Shakeel-Ur-Rehman et al.; Commercial milk protein concentrate (MPC) was used to standardize whole milk for reduced-fat Cheddar cheesemaking . Four replicate cheesemaking trials of three treatments (control, MPC1, and MPC2) were conducted . The control cheese (CC) was made from standardized milk (casein-to-fat ratio, C/F approximately 1.7) obtained by mixing skim milk and whole milk (WM); MPC1 and MPC2 cheeses were made from standardized milk (C/F approximately 1.8) obtained from mixing WM and MPC, except that commercial mesophilic starter was added at the rate of 1% to the CC and MPC1 and 2% to MPC2 vats . The addition of MPC doubled cheese yields and had insignificant effects on fat recoveries (approximately 94% in MPC1 and MPC2 vs . approximately 92% in CC) but increased significantly total solids recoveries (approximately 63% in CC vs . 63% in MPC1 and MPC2) . Although minor differences were noted in the gross composition of the cheeses, both MPC1 and MPC2 cheeses had lower lactose contents (0.25 or 0.32%, respectively) than in CC (0.60%) 7 d post manufacture . Cheeses from all three treatments had approximately 10(9) cfu/g initial starter bacteria count . The nonstarter lactic acid bacteria (NSLAB) grew slowly in MPC1 and MPC2 cheeses during ripening compared to CC, and at the end of 6 mo of ripening, numbers of NSLAB in the CC were 1 to 2 log cycles higher than in MPC1 and MPC2 cheeses . Primary proteolysis, as noted by water-soluble N contents, was markedly slower in MPC1 and MPC2 cheeses compared to CC . The concentrations of total free amino acids were in decreasing order CC > MPC2 > MPC1 cheeses, suggesting slower secondary proteolysis in the MPC cheeses than in CC . Sensory analysis showed that MPC cheeses had lower brothy and bitter scores than CC . Increasing the amount of starter bacteria improved maturity in MPC cheese. Biotechnol Appl Biochem, 2003 Oct, 38(Pt 2), 143 - 9 Caeruloplasmin sterilized by gamma-irradiation in the presence of L-tyrosine maintains structural and catalytic characteristics; Assemand E et al.; It was previously shown that protein aggregation induced by gamma-irradiation can be prevented by L-tyrosine, even when irradiation was done in solution at doses as high as 10 kGy . It is now reported that caeruloplasmin irradiated at low to moderate doses appears more resistant to trypsin-mediated proteolysis than native caeruloplasmin . Ceruloplasmin presents an irradiation-dose-dependent decrease of oxidase activity and a slight increase of ferroxidase activity at low irradiation doses (2 kGy), followed by a decrease at high doses (4-8 kGy) . In all cases, the catalytic activities are higher when caeruloplasmin is irradiated under tyrosine protection . Irradiated caeruloplasmin in the presence of tyrosine preserves its oxidase and ferroxidase activities . Caeruloplasmin irradiated in solution at a dose of 2-3 kGy and higher, in the presence and absence of L-tyrosine, remained sterile during at least 8 weeks of storage at 4 degrees C, as evaluated by the plate-count-agar method for assessing total viable lactic acid bacteria content after incubation for 48 h at 30 degrees C. Appl Microbiol Biotechnol, 2003 Jun, 61(5-6), 502 - 11 Epub 2003 Feb 11. Expression of the Aspergillus niger glucose oxidase gene in Saccharomyces cerevisiae and its potential applications in wine production; Malherbe DF et al.; There is a growing consumer demand for wines containing lower levels of alcohol and chemical preservatives . The objectives of this study were to express the Aspergillus niger gene encoding a glucose oxidase (GOX; beta- d-glucose:oxygen oxidoreductase, EC 1.1.3.4) in Saccharomyces cerevisiae and to evaluate the transformants for lower alcohol production and inhibition of wine spoilage organisms, such as acetic acid bacteria and lactic acid bacteria, during fermentation . The A . niger structural glucose oxidase (gox) gene was cloned into an integration vector (YIp5) containing the yeast mating pheromone alpha-factor secretion signal (MFalpha1(S)) and the phosphoglycerate-kinase-1 gene promoter (PGK1(P)) and terminator (PGK1(T)) . The PGK1(P)- MFalpha1(S)- gox- PGK1(T) cassette (designated GOX1) was introduced into a laboratory strain (Sigma1278) of S . cerevisiae . Yeast transformants were analysed for the production of biologically active glucose oxidase on selective agar plates and in liquid assays . The results indicated that the recombinant glucose oxidase was active and was produced beginning early in the exponential growth phase, leading to a stable level in the stationary phase . The yeast transformants also displayed antimicrobial activity in a plate assay against lactic acid bacteria and acetic acid bacteria . This might be explained by the fact that a final product of the GOX enzymatic reaction is hydrogen peroxide, a known antimicrobial agent . Microvinification with the laboratory yeast transformants resulted in wines containing 1.8-2.0% less alcohol . This was probably due to the production of d-glucono-delta-lactone and gluconic acid from glucose by GOX . These results pave the way for the development of wine yeast starter culture strains for the production of wine with reduced levels of chemical preservatives and alcohol. J Appl Microbiol, 2003, 94(6), 1066 - 71 The survival of silage inoculant lactic acid bacteria in rumen fluid; Weinberg ZG et al.; AIMS: To determine whether lactic acid bacteria (LAB) used in inoculants for silage can survive in rumen fluid (RF), and to identify those that survive best . METHODS AND RESULTS: Twelve commercial silage inoculants were added at 107 CFU ml-1 to strained RF (SRF) taken from dairy cows, with and without 5 g l-1 glucose and incubated in vitro at 39 degrees C . Changes in pH, LAB numbers and fermentation products were monitored for 72 h . In the inoculated RF with glucose, the pH decreased and numbers of LAB increased . The inoculants varied with regard to their effect on pH change and growth . In the SRF, both with and without glucose, the pH values of the inoculated samples were generally higher than those of the uninoculated controls throughout most of the incubation period . This may suggest a positive effect on the rumen environment . CONCLUSIONS: LAB used in silage inoculants can survive in RF in vitro . SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first step in studying the probiotic potential of silage LAB inoculants for dairy cattle . The survival of these LAB in RF may enable them to interact with rumen microorganisms and to affect rumen functionality. Proc Nutr Soc, 2003 Feb, 62(1), 171 - 6 Resistant starch as a prebiotic and synbiotic: state of the art; Topping DL et al.; Non-infectious diseases such as CHD and certain cancers have become major causes of death and disability in affluent countries . Probiotics (principally lactic acid bacteria; LAB) may assist in lowering the risk of these diseases . Experimental studies with probiotics have given generally inconclusive outcomes for infectious disease and for biomarkers for non-infectious disease . In part this situation may reflect their inability to colonise the adult human gut effectively . Prebiotics can assist in promoting colonisation, and resistant starch (RS), as a high-amylose starch, is a prebiotic and synbiotic . This starch exerts its synbiotic action through adhesion of the bacteria to the granule surface . Consumption of RS assists in recovery from infectious diarrhoea in man and animals . A rice porridge, high in RS, appears to modify the autochthonous porcine large-bowel microflora favourably through lowering Escherichia coli and coliform numbers . Many of the beneficial effects of RS on large-bowel function appear to be exerted through short-chain fatty acids (SCFA)formed by bacterial fermentation . In man LAB are found in relatively highest numbers in milk-fed infants where the profile of fermentation products differs quite markedly from that in adults.It appears unlikely that ingestion of current probiotics will alter either total SCFA or the proportions of the major acids . More emphasis needs to be given to the investigation of the effects of complex carbohydrates, including RS, on the autochthonous microflora of the human large bowel. Int J Food Microbiol, 2003 Jun 25, 83(3), 233 - 44 Bioprotectives and probiotics for dry sausages; Tyopponen S et al.; The microbial stability of dry sausages is determined by the combination and timing of different factors referred to as the hurdle-concept . However, the hurdles present in dry sausage are not sufficient to prevent the survival of Listeria monocytogenes or enterohemorrhagic Escherichia coli O157:H7 . Recently bioprotective lactic acid bacteria, which in addition to the production of antimicrobial lactic acid, have been found to contribute to the safety of the dry sausage by producing antimicrobial peptide, i.e . bacteriocins and other low-molecular-mass compounds . Furthermore, the possibilities to use probotics in dry sausage manufacturing process has been addressed recently . As one possible mode of action for probiotics is the production of antimicrobial compounds, lactic acid bacteria may act as both probiotic and bioprotective culture as well as fermenting agent in meat product, such as dry sausage. Nahrung, 2003 Apr, 47(2), 122 - 5 Influence of modified atmosphere packaging on the shelf life of prebaked pizza dough with and without preservative added; Rodriguez V et al.; The possible effect of different modified atmospheres on the shelf life of prebaked pizza dough, with and without added calcium propionate, was investigated . Three packaging atmospheres were tested: 20% CO2: 80% N2, 50% CO2: 50% N2, 100% CO2, and air (control) . Samples were examined daily for visible mold growth and analysed after 2, 8, 17 and 31 days throughout storage (15-20 degrees C and 54-65% relative humidity, RH) for changes in gaseous composition, pH and microbial populations (mesophilic aerobic and anaerobic bacteria, lactic acid bacteria (LAB), and yeasts and molds) . Microbiological results showed that molds had a greater sensitivity to CO2 than bacteria and yeasts . Products containing calcium propionate did not show mold growth throughout storage (31 days) when packaged in air or in CO2-enriched atmospheres (20, 50 and 100%) . However, in pizza dough without preservative (calcium propionate), mold growth was evident after 7 days, except under 100% CO2 atmosphere (13 days) regardless of the packaging atmosphere . From these results we conclude that the addition of calcium propionate had more and decisive influence on the shelf life extension of prebaked pizza dough. Int J Food Microbiol, 2003 Jun 15, 83(2), 115 - 31 Practical implications of lactate and pyruvate metabolism by lactic acid bacteria in food and beverage fermentations; Liu SQ; This article reviews the metabolism of pyruvate and lactate by lactic acid bacteria (LAB) involved in food and beverage fermentations with an emphasis on practical implications . First, the formation of pyruvate and lactate from a range of substrates, including carbohydrates, organic acids and amino acids, is briefly described . The catabolism of pyruvate and lactate by LAB is then reviewed . This is followed by a discussion of lactate degradation and racemisation by LAB from specific fermented foods and beverages . Finally, the impact of environmental factors and metabolic engineering on pyruvate and lactate metabolism by LAB is evaluated with regard to practical significance. FEMS Yeast Res, 2003 Apr, 3(2), 191 - 200 Occurrence and taxonomic characteristics of strains of Saccharomyces cerevisiae predominant in African indigenous fermented foods and beverages; Jespersen L; Indigenous fermented foods and beverages play a major role in the diet of African people . The predominant yeast species seen is Saccharomyces cerevisiae, involved in basically three groups of indigenous fermented products: non-alcoholic starchy foods, alcoholic beverages and fermented milk . These products are to a great extent made by spontaneous fermentation and consequently S . cerevisiae often coexists with other microorganisms even though a microbiological succession usually takes place both between and within species . The functions of S . cerevisiae are mainly related to formation of alcohols and other aroma compounds, but stimulation of e.g . lactic acid bacteria, improvement of nutritional value, probiotic effects, inhibition of undesired microorganisms and production of tissue-degrading enzymes may also be observed . Several different isolates of S . cerevisiae have been shown to be involved in the fermentations and some of the isolates show pheno- and genotypic characteristics that deviate from those normally recognised for S . cerevisiae. Int J Pharm, 2003 Apr 30, 256(1-2), 117 - 22 Optimization of a formulation containing viable lactic acid bacteria; Stadler M et al.; In the present study, gastric juice resistant tablet formulations of lactic acid bacteria (LAB) were developed, using hydroxypropylmethylcellulose acetate succinate (HPMCAS) as well as alginates, apple pectin and Metolose as matrix forming components . To optimize the formulation-using survival rate in acid medium, and disintegration time in intestinal fluid as test parameters-tablets were modified with respect to LAB content, amount of applied excipients per tablet, and compaction forces . A decrease of viable cells of not more than one log unit after 2h of incubation in acid medium was desired, as well as a disintegration time of 1h in phosphate buffer pH 6.8 . It was found that the amount of HPMCAS in the tablet correlates with gastric juice resistance . As HPMCAS also leads to a decrease of disintegration time in intestinal fluid, slight amounts of this excipient were preferred . The best protective qualities against artificial gastric juice were observed when tablets were prepared from compaction mixtures of LAB, HPMCAS and sodium alginate. Lett Appl Microbiol, 2003, 36(5), 307 - 14 Spoilage of bottled red wine by acetic acid bacteria; Bartowsky EJ et al.; AIMS: To determine the bacterial species associated with an outbreak of spoilage in commercially bottled red wine where the bottles had been stored in an upright vertical compared with horizontal position . METHODS AND RESULTS: Bottled wines comprising Cabernet Sauvignon, Pinot Noir, Shiraz, Merlot and blended red varieties were examined for visible spoilage . Analysis of visibly affected and non-affected wines revealed a spectrum of aroma and flavour defects, ranging from loss of fruity aroma, staleness, oxidized character to overt volatile acidity . Only acetic acid bacteria, and not yeast or lactic acid bacteria, could be isolated from both spoiled and unspoiled wines and were found to grow only on Wallerstein Nutrient (WL) medium supplemented with 10% red wine or 1-2% ethanol . Analysis of the 16S rRNA region and RAPD-PCR analysis showed the isolates to be a closely related group of Acetobacter pasteurianus, but this group was differentiated from the group comprising beer, vinegar and cider strains . CONCLUSIONS: A . pasteurianus was the species considered responsible for the spoilage but the isolates obtained had atypical properties for this species . In particular, they failed to grow on WL nutrient medium without ethanol or wine supplementation . Storage of the bottles of wine containing A . pasteurianus in an upright vertical position specifically induced growth and spoilage in a proportion of the bottles under conditions that were inhibitory for horizontally stored bottles . We hypothesize that the upright position created a heterogeneous environment that allowed the growth of bacteria in only those bottles sealed with cork closures that had upper limit for the natural permeability to oxygen . Such a heterogeneous environment would not exist in horizontally stored bottles as the larger volume of wine adjacent to the cork would strongly compete with the bacteria for the oxygen as it diffuses through the cork closure . SIGNIFICANCE AND IMPACT OF THE STUDY: A low level of bacteria (acetic acid bacteria) in wine can proliferate and cause wine spoilage in bottles stored in an upright vertical as opposed to an horizontal position under conditions that would normally limit bacterial development. Lett Appl Microbiol, 2003, 36(5), 288 - 92 Evidence on inhibition of Listeria monocytogenes by divercin V41 action; Richard C et al.; AIMS: The aim of this study was to investigate the role of divercin V41 in inhibition and prevention of Listeria monocytogenes . METHODS AND RESULTS: Carnobacterium divergens V41 deficient in bacteriocin production was isolated and characterized by enzyme-liked immunosorbent assay, multiplex polymerase chain reaction and bacteriocin diffusion test . Carnobacterium divergens V41 (divercin+) and Carnobacterium divergens V41C9 (divercin-) were grown in the presence of L . monocytogenes in smoked salmon model medium . Carnobacterium divergens V41, but not C . divergens V41C9, was able to inhibit growth of L . monocytogenes . The results indicate that inhibition of L . monocytogenes in the presence of C . divergens V41 is because of the production of divercin V41 and not to a nutritional advantage . CONCLUSIONS: Carnobacterium divergens V41 may be a promising agent in food safety . SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates a potential use of a bacteriocin producing lactic acid bacteria in the area food protection. Biotechnol Prog, 2003 Mar-Apr, 19(2), 436 - 9 High production system of the antibacterial peptide PLG-1; Gollop N et al.; Propionibacterium thoenii P-127 produces and releases to the growth medium antibacterial agents that can be used as natural preservatives . The concentrations of these antibacterial agents in the growth medium are very low, and their activity can be detected only in concentrated medium, even in a bioreactor . A simple and efficient system to produce propionicin PLG-1 without the use of a bioreactor was investigated . Fermentation in screw-cap bottles without shaking produced antibacterial activity similar to that of fermentation in plates, but in a shorter time . Sodium lactate medium (NaLa) was found to be the most supportive for PLG-1 production compared to lactic acid bacteria media such as M-17 or beet molasses/corn . The initial concentration of the carbon source, sodium lactate, agar concentration, and the initial pH of the medium affected the synthesis of PLG-1 . Additions of NaCl up to 1% showed no effect on the antibacterial agent production . The optimal conditions for production of the antibacterial agent were fermentation for 9 days in screw-cap bottles in modified NaLa medium (M-NaLa) containing 1% yeast extract, 1% tryptic soy broth, 0.9% lactic acid, and 0.6% agar, adjusted to pH of 9. Biotechnol Bioeng, 2003 May 5, 82(3), 263 - 70 Effects of intermittent addition of cellulase for production of L-lactic acid from wastewater sludge by simultaneous saccharification and fermentation; Nakasaki K et al.; An attempt was made to create L-lactic acid, a precursor of poly-lactic acid, which is a biodegradable plastic, from wastewater sludge from the paper-manufacturing industry . The sludge contained a high percentage of cellulose and needed to be hydrolyzed to glucose by the action of the cellulase before being treating with lactic acid bacteria . Therefore, a method involving simultaneous saccharification and fermentation (SSF) was carried out . The optimum pH of the SSF for production of the lactic acid by the newly isolated lactic acid bacterium with a high selectively of L-lactic acid was found out to be around pH = 5.0, and the optimum temperature to be approximately 40 degrees C . On the basis of the measurement of the cell density changes in the lactic acid bacteria, it was ascertained that the bacterial activity could continue at a high level for a relatively long period of time, and that the L-lactic acid productivity was diminished by the rapid deactivation of the cellulase . With the intermittent addition of cellulase once daily for the sake of compensating for the cellulase deactivation, the L-lactic acid attained a maximum concentration of 16.9 g/L, i.e., a 72.2% yield based on the potential glucose contained in the sludge under optimum pH and temperature conditions . Biochimie, 2002 Nov, 84(11), 1073 - 87 Genetically modified lactic acid bacteria: applications to food or health and risk assessment; Renault P; Lactic acid bacteria have a long history of use in fermented food products . Progress in gene technology allows their modification by introducing new genes or by modifying their metabolic functions . These modifications may lead to improvements in food technology (bacteria better fitted to technological processes, leading to improved organoleptic properties em leader ), or to new applications including bacteria producing therapeutic molecules that could be delivered by mouth . Examples in these two fields will be discussed, at the same time evaluating their potential benefit to society and the possible risks associated with their use . Risk assessment and expected benefits will determine the future use of modified bacteria in the domains of food technology and health. Br J Nutr, 2003 Feb, 89(2), 273 - 81 Demographic and lifestyle characteristics of functional food consumers and dietary supplement users; de Jong N et al.; Functional foods and/or supplements may be used in the context of a healthy lifestyle or as a means to compensate for an unhealthy lifestyle . Adverse long-term and/or cumulative effects of functional food or supplement intake are of public health concern; it is therefore important to identify functional food and supplement users . The present study compared Dutch functional food and supplement consumers with non-consumers with regard to demographic and lifestyle factors . The consumption of the most common functional foods and supplements in 2000 was studied (yoghurt with extra lactic acid bacteria, cholesterol-lowering margarine, lemonade and sweets with extra vitamins and minerals, milk and margarine with extra Ca, Ca tablets, multivitamin and mineral supplements, and Echinacea supplements) . Data were obtained from self-administered questionnaires filled in by a consumer panel, aged 19-91 years (response rate 76 %, n 1183), representative of the Dutch population . The number of daily consumers of functional foods or supplements appeared to be relatively low (daily use of multivitamin and mineral supplements, 20 %; all other products, 3-9 %) . Explanatory variables depended on the type of product; but gender, age, education, and vegetable intake were significant factors in the logistic regression model . Consumption of cholesterol-lowering margarines was more likely to be reported by individuals with a poorer subjective health (odds ratio 2.62 (95 % CI 1.15, 6.05)) and by smokers (odds ratio 2.93 (95 % CI 1.34, 6.40)) . In conclusion, determinants of functional food or supplement use depended on the type of product, so generalisation of consumer characteristics over different foods is not legitimate . In addition to research on lifestyle factors, surveys about consumers' attitudes, norms and knowledge regarding functional foods in relation to actual dietary patterns and health risk profiles are necessary. Curr Pharm Des, 2003, 9(2), 175 - 91 Probiotics as biotherapeutic agents: present knowledge and future prospects; Mercenier A et al.; Since the early observations of Elie Metchnikoff, a wealth of experiments have described the use of selected microorganisms, mainly belonging to the lactic acid bacteria family, for the prevention or treatment of a variety of pathological situations . Nevertheless, the mechanisms underlying the proposed actions remain vastly unknown, partly as a consequence of the complexity of the gastro-intestinal ecosystem with which these biotherapeutic agents are expected to interact, but also because of the increasing variety of strains considered to have potential probiotic characteristics . During the past decades, however, the beneficial effect of specific strains in preventing or treating intestinal disorders has been substantiated by well-controlled clinical trials . Increasing evidence, including human studies, is also supporting the immunomodulatory role attributed to given lactic acid bacterial strains . The desire by consumers to use natural methods for health maintenance rather than long-term chemotherapeutic agents (i.e . antibiotics), linked to their expectation that food becomes a source of prolonged well-being, supports the speculation that the probiotic market will expand rapidly . Much of this growth will also depend on the reliability of claims that these products will bare . Therefore, the legislator will have to provide clear rules and regulations which will depend on measurable biomarkers and criteria based on scientific evidence . These commercial and legislative needs will hopefully provide scientists with the resources necessary to conduct the multidisciplinary research required to establish facts and mechanisms of action for carefully selected probiotic strains . These research results will probably be as essential for the positioning of probiotic preparations as either a food, a food supplement or as pharmaceutical preparation. Wei Sheng Yan Jiu, 2002 Apr, 31(2), 122 - 3 {A simple method for screening of highly inhibitory Lactic acid bacteria on Aspergillus flavus growth}; Xu J et al.; A simple and rapid method for screening of Lactic acid bacteria with high inhibitory power is developed . The methodology employed was the agar-diffusion assay, which was standardized for medium composition, and incubation conditions . The assay was composed of two layers of medium, MRS agar at the bottom of plate, PDA at the top of MRS agar . Lactic acid bacteria culture was inoculated to the media between MRS and PDA, then a known number of mold spores was surface plated on PDA plates, and incubated at 25 degrees C for 72 h. Wei Sheng Wu Xue Bao, 2001 Feb, 41(1), 101 - 4 {The construction and application of promoter-signal peptide probe vector of lactic acid bacteria}; Chen X et al.; A promoter-signal peptide probe vector of lactic acid bacteria, designated pZLB based on pMG36e has been constructed . The vector contained a reporterd gene encoding for beta-lactamase, which lacked a promoter and a functional signal sequence . Sau3A restriction fragments (80-400 bp) from L . lactis ATCC 7962 total DNA were cloned into BamHI site of pZLB . A lot of different size framents were selected . These fragments promoted transcription and secretion of beta-lactamase in L . lactis . Sequence analysis revealed that inserted fragment in pZLBe7 contained typical promoter, SD sequence and atypical signal sequence. Wei Sheng Yan Jiu, 2002 Jun, 31(3), 211 - 3 {Biological synthesis and application of bacteriocins}; Xu J et al.; Bacteriocins produced by lactic acid bacteria are a heterogeneous group of peptide inhibitors . Most of bacteriocins have relatively narrow inhibitory spectra . A few of them have wider inhibitory spectra, being active against a wide range of gram-positive bacteria . Bacteriocins can be divided into three types . There are small heat-stable peptides, large heat-labile proteins, and lantibiotics . Their physico-chemical nature, genetic behavior and application are reviewed. J Microbiol Methods, 2003 Mar, 52(3), 333 - 9 An improved method for the determination of NADH oxidase in the presence of NADH peroxidase in lactic acid bacteria; Talwalkar A et al.; The complexity of the coupled NADH oxidase-NADH peroxidase enzyme system in lactic acid bacteria makes it difficult to simultaneously determine the individual levels of both these enzymes spectrophotometrically . This study describes an improved assay to accurately determine low concentrations of NADH oxidase from enzyme suspensions containing NADH oxidase and NADH peroxidase . For the standardisation of the assay, pure NADH oxidase and NADH peroxidase were mixed in various proportions and the percentage recovery was estimated by both the currently available assay as well as by the improved assay reported in this study . The recovery of NADH oxidase using the currently available assay ranged from as low as -200% to as high as +102% as against 90-102% in the improved assay . The recovery percentage of NADH peroxidase ranged from 91% to 112% in both assays . The slopes of NADH oxidation by cell-free extracts of six lactic acid bacteria were also measured by both assays for the estimation of NADH oxidase and NADH peroxidase levels . The improved assay can further distinguish between NADH-H(2)O oxidase and NADH-H(2)O(2) oxidase and was successfully applied to identify the type of NADH oxidase in the lactic acid bacteria tested. Microbiol Immunol, 2002, 46(11), 723 - 31 Role of internalization in the pathogenicity of Shiga toxin-producing Escherichia coli infection in a gnotobiotic murine model; Aiba Y et al.; We investigated the role of bacterial internalization in the killing caused by Shiga toxin-producing Escherichia coli (STEC) infection using a gnotobiotic murine model . A high number of internalized STEC was found in the colonic epithelial cells of STEC-infected mice by both an ex vivo assay and transmission electron microscopy . Most of these mice were killed within 10 days after infection . However, the implantation of lactic acid bacteria in such mice before infection markedly decreased the number of internalized STECs and also completely protected these hosts from killing by a STEC infection . The inhibition of such internalization by immunoglobulin also prevented the hosts from being killed . The Shiga toxin levels in these hosts indicated an inhibition of the penetration of Shiga toxins produced in the colon to the underlying tissue . These results suggested that the internalization plays an important role in the pathogenicity caused by STEC infection in a gnotobiotic murine model. J Nutr, 2003 Jan, 133(1), 21 - 7 The prebiotic characteristics of fructooligosaccharides are necessary for reduction of TNBS-induced colitis in rats; Cherbut C et al.; Fructooligosaccharides (FOS) increase the growth of lactic acid bacteria (LAB) and promote butyrate and lactate production . Because of these properties, FOS may benefit intestinal inflammation . The purpose of this study was to investigate the effect of FOS on colitis in rats and determine which factors are involved . Groups of rats with intracolonic trinitrobenzene sulfonic acid (TNBS)-induced colitis received intragastric infusions of 9 g/L NaCl, 1 g/d FOS or 10(11) colony-forming units (cfu)/d LAB (Experiment 1), or intracolonic infusions of 9 g/L NaCl, butyrate, lactate or butyrate + lactate with or without 10(9.5) cfu/d LAB (Experiment 2) . Each infusion was administered twice daily for 14 d . Intragastric FOS reduced the gross score for inflammation (P < 0.001), myeloperoxidase (MPO) activity (P < 0.001) and pH (P < 0.001), and increased lactate (P = 0.02) and butyrate concentrations (P < 0.001) as well as LAB counts in the cecum (P < 0.01) . Intragastric LAB (10(11) cfu/d) had the same beneficial effects as FOS and modified the cecal composition similarly . High doses of intracolonic butyrate and lactate reduced the indices of inflammation (P < 0.001), whereas administration of the lower concentrations found in the colon tended to decrease (P < 0.1) the gross score for inflammation and MPO activity . Addition of LAB (10(9.5) cfu/d) to the organic acids was necessary to reproduce the significant FOS-induced effects on these variables . Thus, under the experimental conditions used, FOS reduced intestinal inflammatory activity mainly by increasing LAB counts in the intestine. J Gen Appl Microbiol, 1998 Dec, 44(6), 371 - 374 The ratio of L-form to D-form of lactic acid as a criteria for the identification of lactic acid bacteria; Manome A et al.; Stereoisomers of lactic acid produced by lactic acid bacteria were determined by HPLC by using an enantiomeric resolution column . In general, the ratios of L-form to D-form (the type of stereoisomer) obtained were compared with those in references . Values of the type of stereoisomer of lactic acid were discussed from the viewpoint of identification of lactic acid bacteria. Gig Sanit, 2002 Sep-Oct, (5), 54 - 6 {Hygienic characterization of lactic acid bacteria products prepared by using hydrolysates of raw milk and soya bean materials}; Tsinberg MB et al.; The paper reflects the results of a comparative study of preparations of lactic acid bacteria (LAB), which are based on the hydrolysates of raw milk and soya bean materials, by using methods to determine the organoleptic and physicochemical properties, microbiological characteristics including the titer of microbial cells per ml of the preparation and the presence/absence of representatives of sanitary significant groups of microorganisms, the persistent properties of microorganisms . By summarizing the findings, it can be stated that it is possible to use a raw soya-bean hydrolysate-based nutrient medium to cultivate technical LAB strains with the compliance of the toxicological and microbiological parameters of the prepared preparations with the current sanitary standards . The LAB preparations grown on the hydrolysate-soya-bean medium have been protected with the patents of Russia . Their biological properties are highly competitive with those and, in some cases, superior to hydrolysate-milk medium-based preparations . This presents in their adhesive potential and in the formation of more pronounced antagonistic properties against opportunistic microorganisms. Antonie Van Leeuwenhoek, 2002 Aug, 81(1-4), 639 - 54 Production of class II bacteriocins by lactic acid bacteria; an example of biological warfare and communication; Eijsink VG et al.; Lactic acid bacteria (LAB) fight competing Gram-positive microorganisms by secreting anti-microbial peptides called bacteriocins . Peptide bacteriocins are usually divided into lantibiotics (class I) and non-lantibiotics (class II), the latter being the main topic of this review . During the past decade many of these bacteriocins have been isolated and characterized, and elements of the genetic mechanisms behind bacteriocin production have been unravelled . Bacteriocins often have a narrow inhibitory spectrum, and are normally most active towards closely related bacteria likely to occur in the same ecological niche . Lactic acid bacteria seem to compensate for these narrow inhibitory spectra by producing several bacteriocins belonging to different classes and having different inhibitory spectra . The latter may also help in counteracting the possible development of resistance mechanisms in target organisms . In many strains, bacteriocin production is controlled in a cell-density dependent manner, using a secreted peptide-pheromone for quorum-sensing . The sensing of its own growth, which is likely to be comparable to that of related species, enables the producing organism to switch on bacteriocin production at times when competition for nutrients is likely to become more severe . Although today a lot is known about LAB bacteriocins and the regulation of their production, several fundamental questions remain to be solved . These include questions regarding mechanisms of immunity and resistance, as well as the molecular basis of target-cell specificity. Biochimie, 2002 May-Jun, 84(5-6), 593 - 604 Potential of bacteriocin-producing lactic acid bacteria for improvements in food safety and quality; O'Sullivan L et al.; Lactic acid bacteria (LAB) have been used for centuries in the fermentation of a variety of dairy products . The preservative ability of LAB in foods is attributed to the production of anti-microbial metabolites including organic acids and bacteriocins . Bacteriocins generally exert their anti-microbial action by interfering with the cell wall or the membrane of target organisms, either by inhibiting cell wall biosynthesis or causing pore formation, subsequently resulting in death . The incorporation of bacteriocins as a biopreservative ingredient into model food systems has been studied extensively and has been shown to be effective in the control of pathogenic and spoilage microorganisms . However, a more practical and economic option of incorporating bacteriocins into foods can be the direct addition of bacteriocin-producing cultures into food . This paper presents an overview of the potential for using bacteriocin-producing LAB in foods for the improvement of the safety and quality of the final product . It describes the different genera of LAB with potential as biopreservatives, and presents an up-to-date classification system for the bacteriocins they produce . While the problems associated with the use of some bacteriocin-producing cultures in certain foods are elucidated, so also are the situations in which incorporation of the bacteriocin-producer into model food systems have been shown to be very effective. Biochimie, 2002 May-Jun, 84(5-6), 577 - 92 Two-peptide bacteriocins produced by lactic acid bacteria; Garneau S et al.; Bacteriocins from lactic acid bacteria are ribosomally produced peptides (usually 30-60 amino acids) that display potent antimicrobial activity against certain other Gram-positive organisms . They function by disruption of the membrane of their targets, mediated in at least some cases by interaction of the peptide with a chiral receptor molecule (e.g., lipid II or sugar PTS proteins) . Some bacteriocins are unmodified (except for disulfide bridges), whereas others (i.e . lantibiotics) possess extensive post-translational modifications which include multiple monosulfide (lanthionine) bridges and dehydro amino acids as well as possible keto amide residues at the N-terminus . Most known bacteriocins are biologically active as single peptides . However, there is a growing class of two peptide systems, both unmodified and lantibiotic, which are fully active only when both partners are present (usually 1:1) . In some cases, neither peptide has activity by itself, whereas in others, the activity of one is enhanced by the other . This review discusses the classification, structure, production, regulation, biological activity, and potential applications of such two-peptide bacteriocins. Biochimie, 2002 May-Jun, 84(5-6), 357 - 64 Bacteriocin diversity: ecological and evolutionary perspectives; Riley MA et al.; The bacteriocin family is the most abundant and diverse group of bacterial defense systems . Bacteriocins range from the well-studied narrow spectrum, high molecular weight colicins produced by Escherichia coli and the short polypeptide lantibiotics of lactic acid bacteria to the relatively unknown halocins produced almost universally by the haolobacteria . The abundance and diversity of this potent arsenal of weapons is clear . Less clear is their evolutionary origins and the role they play in mediating microbial interactions . The goal of this review is to explore what we know about the evolution and ecology of the best-characterized family of bacteriocins, the colicins . We summarize current knowledge of how such extraordinary protein diversity arose and is maintained in microbial populations and what role these toxins play in mediating microbial population-level and community-level dynamics. J Agric Food Chem, 2002 Nov 6, 50(23), 6835 - 40 Important aroma compounds in freshly ground wholemeal and white wheat flour-identification and quantitative changes during sourdough fermentation; Czerny M et al.; An investigation on the odor-active compounds of wholemeal (WWF) and white wheat flour (WF 550) by aroma extract dilution analysis (AEDA) and by quantitative studies using stable isotope dilution assays (SIDA) revealed a significant number of odor-active compounds, such as (E)-2-nonenal, (E,Z)- and (E,E)-2,4-decadienal, (E)-4,5-epoxy-(E)-2-decenal, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, and vanillin, with high odor activities in both wheat flours . The amounts and, consequently, the aroma potencies of vanillin, (E,E)-2,4-decadienal, and 3-(methylthio)propanal were much higher in the WWF than in the WF 550 samples . Fermentation of suspensions of both flours with lactic acid bacteria did not generate new odorants; however, many compounds, such as acetic acid or 3-methylbutanal, were increased, whereas aldehydes (formed from the degradation of unsaturated fatty acids) were decreased . Comparing the odorant concentrations present before and after fermentation gave evidence that the main influence of the microorganisms on sourdough aroma is to either enhance or decrease specific volatiles already present in the flour . A comparison with literature data indicated that most of these odorants are also important for the bread crumb aroma present after baking of the dough. Sheng Wu Gong Cheng Xue Bao, 2002 Jul, 18(4), 516 - 20 {Food-grade gene expression systems for lactic acid bacteria}; Zhang ZZ et al.; Lactic acid bacteria (LAB) are important industrial microorganism used in the production and preservation of food-stuffs . Recently, considerable advances have been made in the genetics and molecular biology of LAB . These have resulted in the construction of food-grade gene expression systems for these bacteria . This paper aims to review the essential features for food-grade systems, food-grade selection markers, food-grade controlled gene expression and food-grade inducible signaling molecule, and recent developments on food-grade cloning and expression systems for LAB . These gene expression systems have great potential for studies on gene expression and regulation in LAB and a variety of bioprocessing application in industrial fermentations. Int J Food Microbiol, 2002 Nov 15, 79(1-2), 113 - 9 Microflora of date fruits and production of aflatoxins at various stages of maturation; Shenasi M et al.; Twenty-five varieties of dates (Phoenix dactylifera) were examined at different maturation stages for total microbial counts, aflatoxins and aflatoxigenic Aspergillus sp . and lactic acid bacteria . The samples were examined as fresh and under simulated storage condition of high humidity . Microbial counts were high at the first stage of maturation (Kimri) and increased sharply at the second stage (Rutab), then decrease significantly at the final dried stage of maturation (Tamr) . Aflatoxins were detected in 12% of the samples although aflatoxigenic Aspergillus were detected in 40% of the varieties examined, all at Kimri stage only . Lactic acid bacteria were present only at the Rutab stage in some varieties including all varieties in which aflatoxins or aflatoxigenic Aspergillus were detected . No aflatoxins or aflatoxigenic Aspergillus were detected at the final edible stage of maturation. Int J Food Microbiol, 2003 Jan 25, 80(2), 101 - 16 Heterologous production of bacteriocins by lactic acid bacteria; Rodriguez JM et al.; Over the last two decades, bacteriocins produced by lactic acid bacteria (LAB) have been the subject of considerable research and industrial interest due to their potential as food biopreservatives . The development of heterologous expression systems for such antimicrobial compounds may offer a number of advantages over native systems, such as facilitating the control of bacteriocin gene expression or achieving higher production levels . In addition, the heterologous production by food-grade LAB offers an attractive method for overcoming some of the adverse situations that may affect the effectiveness of some bacteriocins in food systems . Construction of multibacteriocinogenic strains or acquisition of antimicrobial properties by industrial strains are further objectives that can be achieved through the use of heterologous gene expression systems . The development of new biotechnological tools and recent advances in LAB genetics account for the escalating number of studies dealing with heterologous production of bacteriocins by such hosts . This paper reviews the literature published on the subject and compares the different experimental strategies that have been used up to the present for this purpose. Antonie Van Leeuwenhoek, 2002 Aug, 82(1-4), 59 - 71 Global control of sugar metabolism: a gram-positive solution; Titgemeyer F et al.; Bacteria utilise carbon sources in a strictly controlled hierarchical manner for which they have developed global control mechanisms that govern and coordinate carbon source-specific regulation . This is achieved via carbon catabolite repression (CCR), which is the result of global transcriptional control and inducer exclusion . A common mechanism for transcriptional control has evolved within the group of low-GC Gram-positive bacteria, including lactic acid bacteria . The seryl-phosphorylated form of the phosphotransferase HPr (HPr-ser-P) mediates CCR in concert with the pleiotropic regulator CcpA (catabolite control protein) by repressing or activating catabolite-controlled genes . HPr-ser-P can concomitantly trigger inducer exclusion by inhibition of carbohydrate-specific permeases . Histidyl-phosphorylated HPr (HPr-his P) is required for the transport of many carbon sources by the phosphotransferase system (PTS) . In addition, HPr-his P controls carbohydrate-specific regulators and catabolic enzymes by phosphorylation . Thus, the ratio of HPr-his P/HPr-ser-P determines utilisation of a particular carbon source . This ratio is mainly adjusted by the bifunctional HPr kinase/phosphatase (HPrK/P), which itself is controlled by the metabolic state of the cell . As a result, the information about the metabolic state of the cell is combined with signals scoring the availability of carbon sources to fine-tune the expression of catabolic genes with the goal to optimise growth rate in any given mixture of nutrients . This review summarises the current understanding of carbon catabolite regulation in low-GC Gram-positive bacteria with special emphasis on lactic acid bacteria. Antonie Van Leeuwenhoek, 2002 Aug, 82(1-4), 367 - 74 Exploiting expolysaccharides from lactic acid bacteria; Jolly L et al.; Microbial exopolysaccharides (EPSs) synthesized by lactic acid bacteria (LAB) play a major role in the manufacturing of fermented dairy products . EPS production is characterized by a large variety in terms of quantity, chemical composition, molecular size, charge, type of sidechains and rigidity of the molecules . Monosaccharide unit's composition, linkages, charge and size determine the EPS' intrinsic properties and their interactions with other milk constituents . EPSs contribute to texture, mouthfeel, taste perception and stability of the final product . Furthermore, it was reported that EPS from food grade organisms, particularly LAB, have potential as food additives and as functional food ingredients with both health and economic benefits . A better understanding of structure-function relationships of EPS in a dairy food matrix and of EPS biosynthesis remain two major challenges for further applications of EPS and the engineering of functional polysaccharides. Antonie Van Leeuwenhoek, 2002 Aug, 82(1-4), 353 - 60 Lactic acid bacteria in a changing legislative environment; Feord J; The benefits of using lactic acid bacteria in the food chain, both through direct consumption and production of ingredients, are increasingly recognised by the food industry and consumers alike . The regulatory environment surrounding these products is diverse, covering foods and food ingredients, processing aids, feed additives and dietary supplements . On a global basis, there are different approaches taken by the various regulatory authorities . While in Europe, the national legislation is gradually being harmonized, predominantly through the Novel Foods Regulation, there is still a wide disparity between the stringency of regulation of microbial products fed to animals and the comparatively relaxed approach to 'non-novel' microbial products intended for human consumption . In the United States, the onus is on self-regulation of the manufacturer, with the Generally Recognised As Safe (GRAS) and Dietary Supplement Health Education Act (DSHEA) notification schemes encouraging industry to be more open about the ingredients they market . In Japan, the Foods for Special Health Use system continues to gain recognition as more products are approved, and is a potential model for other countries in regulating functional foods . Despite the different approaches to regulating these products, safety of microorganisms such as lactic acid bacteria in the food chain is paramount in all countries . This paper discusses the regulatory requirements of microbial products, predominantly lactic acid bacteria within the global markets, focusing mainly on the developments in Europe. Antonie Van Leeuwenhoek, 2002 Aug, 82(1-4), 3 - 27 The cell membrane and the struggle for life of lactic acid bacteria; Konings WN; The major life-threatening event for lactic acid bacteria (LAB) in their natural environment is the depletion of their energy sources and LAB can survive such conditions only for a short period of time . During periods of starvation LAB can exploit optimally the potential energy sources in their environment usually by applying proton motive force generating membrane transport systems . These systems include in addition to the proton translocating F0F1-ATPase: a respiratory chain when hemin is present in the medium, electrogenic solute uptake and excretion systems, electrogenic lactate/proton symport and precursor/product exchange systems . Most of these metabolic energy-generating systems offer as additional bonus the prevention of a lethal decrease of the internal and ex