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J Biochem (Tokyo), 1997 Jun, 121(6), 1155 - 61 Cloning and expression of the glutamate racemase gene of Bacillus pumilus; Liu L et al.; A glutamate racemase gene (murI) was found in Bacillus pumilus cells and cloned into Escherichia coli WM335, a D-glutamate auxotroph, by means of a genetic complement method . MurI of B . pumilus encodes a 272-amino acid protein with an unusual initiation codon, TTG . The deduced amino acid sequence shows significant similarity with those of glutamate racemases from E . coli (ratio of identical residues, 28%), Pediococcus pentosaceus (44%), and Staphylococcus haemolyticus (49%) . B . pumilus MurI was expressed as a fusion protein connected to the N-terminal 12 residues of beta-galactosidase; the fusion protein showed glutamate racemase activity, and resembled the enzyme of P . pentosaceus in physicochemical and enzymological properties. J Clin Microbiol, 1997 Aug, 35(8), 2026 - 30 Rapid characterization schemes for surveillance isolates of vancomycin-resistant enterococci; Sahm DF et al.; Surveillance cultures for vancomycin-resistant enterococci (VRE) and subsequent characterization of the isolates can be extremely burdensome and difficult . Therefore, efficient and reliable schemes for the characterization of surveillance isolates are needed . In this study, a commercial agar (bile esculin azide agar with 6 microg of vancomycin per ml {BEAA}; Remel, Lenexa, Kans.) was used in the initial screening step to establish relatively rapid (i.e., in < or = 24 h from the time of isolation) phenotype-based and PCR-based schemes for the detection and characterization of VRE . The phenotype-based scheme included Gram staining of growth on BEAA and subculture of cocci on sheep blood agar plates for vancomycin disk diffusion and pyrazinamidase (PYR) testing . For the PCR scheme, inocula for van gene detection were taken directly from the BEAA plates . The phenotypic approach was applied to 378 surveillance cultures that yielded growth on BEAA . Gram staining quickly eliminated gram-positive bacilli from further testing, and a negative PYR test classified 25 additional isolates as probable pediococci . A positive PYR test reliably identified 121 single-patient VRE isolates that included 83 Enterococcus faecium, 33 E . gallinarum, and 5 E . casseliflavus strains . The vancomycin inhibition zone size clearly distinguished VanA and VanB strains from VanC strains within 24 h of BEAA isolation . All VanA and VanB strains failed to produce zones of >6 mm, while only one VanC strain produced a zone of < 15 mm . Challenging this phenotypic scheme with 47 stock VRE isolates produced similar findings . In direct PCR analyses, false-negative vanA and vanB results occurred with 12% of the specimens . Many of the false-negative reactions also failed to produce an internal control product, which underscores the need for including control primers when a PCR scheme is used . In summary, the phenotype- and the PCR-based schemes provide efficient methods for characterizing VRE within 24 h of isolation. Int J Food Microbiol, 1997 Jun 17, 37(1), 47 - 54 Viability of Escherichia coli O157:H7 in pepperoni during the manufacture of sticks and the subsequent storage of slices at 21, 4 and -20 degrees C under air, vacuum and CO2; Faith NG et al.; A raw, pepperoni batter (75% pork:25% beef with a fat content of about 32%) was inoculated with a pediococcal starter culture (about 10(8) cfu/g) and a five-strain cocktail of Escherichia coli O157:H7 (> or = 2 x 10(7) cfu/g), mixed with non-meat ingredients, and then hand-stuffed into 55 mm fibrous casings to form sticks . The numbers of the pathogen were determined before stuffing, after fermentation, after drying/slicing, and after periods of storage . For storage, slices were packaged under air, vacuum or CO2 and stored at -20, 4 and 21 degrees C . Sticks were fermented at 36 degrees C and 85% relative humidity (RH) to < or = pH 4.8 and then dried at 13 degrees C and 65% RH to a moisture/protein ratio (M/Pr) of < or = 1.6:1 . Fermentation and drying resulted in the numbers of the pathogen decreasing by about 2 log10 units . During storage, the temperature rather than the atmosphere had the greater effect on pathogen numbers . The greatest reductions in numbers were observed during storage at 21 degrees C, when numbers decreased to about 2 and 3.8 log10 cfu/g within 14 days in product stored under air and vacuum, respectively, and a 5 log10 reduction was observed for both atmospheres within 28 days . Regardless of the storage atmosphere, numbers did not decrease below 3.6 or 3.7 log10 cfu/g after 90 days of storage at -20 or 4 degrees C, respectively . These data confirm that fermentation and drying are sufficient to eliminate only about 2 log10 cfu/g of E . coli O157:H7 from fermented sausage, and that additional strategies, such as storage for at least 2 weeks at ambient temperature in air, are required to achieve a 5 to 6 log10 reduction in the numbers of the pathogen in sliced pepperoni. Biosci Biotechnol Biochem, 1997 Jun, 61(6), 1049 - 51 A bacteriocin of strain Pediococcus sp . ISK-1 isolated from Nukadoko, bed of fermented rice bran; Kimura H et al.; Pediococcus sp . ISK-1 isolated in our laboratory from well-aged Nukadoko, produces a bacteriocin which has a unique antimicrobial spectrum among pediocins . The bacteriocin was stable at acidic pH, and more than 60% of antimicrobial activity still remained even after being autoclaved at 121 degrees C for 20 min in the pH range of 3 to 8 . This is the first report dealing with a bacteriocin produced by lactic acid bacteria isolated from Nukadoko. Biosci Biotechnol Biochem, 1997 Apr, 61(4), 604 - 8 Optimization of the culture medium for growth and the kinetics of lactate fermentation by Pediococcus sp . ISK-1; Herawati E et al.; The growth of a newly isolated strain of Pediococcus sp., designated ISK-1, was very slow and the concentration of cells in the medium remained low . Fermentation with an initial 30 g/liter glucose required about 60 h . To stimulate fermentation, we attempted to optimize the medium by flask culture and jar fermentation tests . Mevalonic acid and mieki (soy bean hydrolyzate) stimulated fermentation and increased the rate of formation of DL-lactate . Kinetic analysis of the fermentation showed that mevalonic acid markedly increased the specific glucose consumption rate and the specific lactate production rate . Mieki and mevalonic acid had a synergistic effect, but the effect of mevalonic acid was different from that of mieki. J Appl Bacteriol, 1996 Jun, 80(6), 635 - 44 Pediocin 5 production and plasmid stability during continuous free and immobilized cell cultures of Pediococcus acidilactici UL5; Huang J et al.; Continuous production of pediocin 5 from Pediococcus acidilactici UL5 was investigated in MRS medium at different pH and dilution rates during continuous free cell (FC) and immobilized cell (IC) fermentations . Pediocin 5 activity from FC operated at a dilution rate of 0.31 h-1 largely increased from 128 to 2048 AU mL-1 as pH decreased from 7.0 to 5.0 . Pediocin 5 activity in IC at a dilution rate of 0.93 h-1 was much less affected by pH, varying from 256 AU mL-1 at pH 7.0 to 512 AU mL-1 at pH 5.0 . At the optimum pH 5.0, the dilution rate greatly influenced pediocin 5 activity both in FC and IC . Pediocin 5 production during continuous FC culture decreased with time for all dilution rates tested except 0.31 h-1 and average activity over 144 h cultures reached a maximal value of 4915 AU mL-1 at a dilution rate of 0.26 h-1 . For IC, pediocin 5 production was stable with time and increased with the dilution rate from 256 to 1024 AU mL-1 in the range of 0.47-2.28 h-1 . Three Listeria strains were tested for their ability to screen low bacteriocin-producing variants (Bac+v) of Bac+ cells in FC and IC cultures by using a modified deferred antagonism method . Ten to 28% of Bac+v cells appeared after 144 h of FC cultures at dilution rates in the range 0.09-0.42 h-1 and pH control set points of 5.0-7.0 while almost no Bac+v cell was detected during 192 h IC culture in the same pH range and for dilution rates varying from 0.47 to 2.28 h-1 . The Bac+v cells isolated produced eight- to 64-fold less pediocin 5 than the Bac+ cells . Although electrophoresis analysis showed no apparent difference in the plasmid profiles of Bac+v and Bac+ cells, the Bac- mutant obtained by acriflavine treatment had lost the pMJ5 plasmid encoding for bacteriocin production . The decreased quantity of plasmid DNA in Bac+v cells suggests that the decreased pediocin 5 activity of Bac+v cells resulted from a decrease in plasmid copy number. Int J Food Microbiol, 1995 Oct, 27(2-3), 101 - 6 Polysaccharide production by Pediococcus pentosaceus from wine; Manca de Nadra MC et al.; Two polymer-forming strains of Pediococcus pentosaceus from Argentinian wines were grown under different conditions . Polysaccharides were produced independently of carbon source at the early logarithmic phase of growth . With the presence of ethanol and SO2, the specific polymers production was greater . The polysaccharides comprised of glucose, fructose and galactose, with predominant linkages of alpha-1,4- and alpha-1,6-glucosidic with a ratio 1:1 . They contained approximately 5500 hexose molecules. J Ind Microbiol, 1995 Sep, 15(3), 227 - 33 Influences on the antimicrobial activity of surface-adsorbed nisin; Bower CK et al.; The efficacy of the antimicrobial peptide nisin was examined after adsorption to silica surfaces . Three protocols were used to evaluate nisin's activity against adhered cells of Listeria monocytogenes: bioassay using Pediococcus pentosaceous FBB 61-2 as the sensitive indicator strain; visualization and enumeration of cells by microscopic image analysis; and viability of adhered cells as determined by lodonitrotetrazolium violet uptake and crystallization . The activity of adsorbed nisin was highly dependent upon conditions of adsorption . The highest antimicrobial activity of adsorbed nisin occurred with high concentrations of nisin (1.0 mg ml-1) and brief contact times (1 h) on surfaces of low hydrophobicity . Sequential adsorption of a second protein (beta-lactoglobulin or bovine serum albumin) onto surfaces consistently resulted in decreased nisin activity . These data provide direction for the development of applications to limit microbial attachment on food contact surfaces through the use of adsorbed antimicrobial peptides. Mol Microbiol, 1995 Aug, 17(3), 515 - 22 Functional analysis of the pediocin operon of Pediococcus acidilactici PAC1.0: PedB is the immunity protein and PedD is the precursor processing enzyme; Venema K et al.; The bacteriocin pediocin PA-1 operon of Pediococcus acidilactici PAC1.0 encompasses four genes: pedA, pedB, pedC and pedD . Transcription of the operon results in the formation of two overlapping transcripts, probably originating from a single promoter upstream of pedA . The major transcript comprises pedA, pedB, and pedC, while a minor transcript encompasses all of these genes and pedD . By deletion analysis and overexpression of pedB in Pediococcus pentosaceus we demonstrate that this gene encodes the pediocin PA-1 immunity protein . Prepediocin is active in Escherichia coli and when pedA was expressed concomitantly with pedD both the precursor and the mature form of pediocin were observed intracellularly . Extracellular pediocin was only detected if both pedC and pedD were present . The N-terminal domains of PedD and a subgroup of bacteriocin ABC-transporters are conserved . Expression of only this domain of PedD in cells producing prepediocin was sufficient for prepediocin processing . From these results we conclude that both PedC and PedD are essential for pediocin transport, and that PedD is capable of processing prepediocin. Appl Environ Microbiol, 1995 Jul, 61(7), 2643 - 8 Isolation and characterization of pediocin L50, a new bacteriocin from Pediococcus acidilactici with a broad inhibitory spectrum; Cintas LM et al.; Lactic acid bacteria were isolated from Spanish dry-fermented sausages and screened for bacteriocin production . About 10% of the isolates produced antimicrobial substances when grown on solid media, but only 2% produced detectable activity in liquid media . Strain L50, identified as Pediococcus acidilactici, showed the strongest inhibitory activity and was active against members of all of the gram-positive genera tested . The strain produced a heat-stable bacteriocin when grown at 8 to 32 degrees C but not at 45 degrees C . The bacteriocin was purified to homogeneity . Its mass was determined to be 5,250.11 +/- 0.30 by electrospray mass spectrometry . The N terminus of the bacteriocin was blocked for sequencing by Edman degradation, but a partial sequence of 42 amino acids was obtained after cleavage of the peptide by cyanogen bromide . The sequence showed no similarity to those of other bacteriocins . Pediocin L50 appears to contain modified amino acids but not lanthionine or methyl-lanthionine. J Appl Bacteriol, 1995 Jun, 78(6), 616 - 20 Effect of Pediococcus pentosaceus FBB61, pediocin A producer strain, in caecal fermentations; Piva A et al.; The objective of this study was to investigate the effect of pediocin A in in vitro caecal fermentations . Pediococcus pentosaceus FBB61, pediocin A producer (bac+) and its isogenic mutant (bac-) Ped . pentosaceus FBB61-2 were added to fermentation vessels . Pediocin A did not alter the normal activity of caecal microflora . Nevertheless, the presence of pediocin A producer strain reduced proteolysis compared to the mutant strain as indicated by ammonia concentrations (P < 0.05), and isobutyric and isovaleric molar proportions (P < 0.05). J Bacteriol, 1995 Jun, 177(12), 3427 - 37 Pediococcus acidilactici ldhD gene: cloning, nucleotide sequence, and transcriptional analysis; Garmyn D et al.; The gene encoding D-lactate dehydrogenase was isolated on a 2.9-kb insert from a library of Pediococcus acidilactici DNA by complementation for growth under anaerobiosis of an Escherichia coli lactate dehydrogenase and pyruvate-formate lyase double mutant . The nucleotide sequence of ldhD encodes a protein of 331 amino acids (predicted molecular mass of 37,210 Da) which shows similarity to the family of D-2-hydroxyacid dehydrogenases . The enzyme encoded by the cloned fragment is equally active on pyruvate and hydroxypyruvate, indicating that the enzyme has both D-lactate and D-glycerate dehydrogenase activities . Three other open reading frames were found in the 2.9-kb insert, one of which (rpsB) is highly similar to bacterial genes coding for ribosomal protein S2 . Northern (RNA) blotting analyses indicated the presence of a 2-kb dicistronic transcript of ldhD (a metabolic gene) and rpsB (a putative ribosomal protein gene) together with a 1-kb monocistronic rpsB mRNA . These transcripts are abundant in the early phase of exponential growth but steadily fade away to disappear in the stationary phase . Primer extension analysis identified two distinct promoters driving either cotranscription of ldhD and rpsB or transcription of rpsB alone. J Appl Bacteriol, 1995 May, 78(5), 473 - 6 Production and stability of pediocin N5p in grape juice medium; Strasser de Saad AM et al.; The production and stability of pediocin N5p from Pediococcus pentosaceus, isolated from wine, were examined in grape juice medium . Maximum growth and higher titre (4000 U ml-1) were observed at a initial pH of 7.5 and 30 degrees C . The activity of the inhibitory substance was stable between pH values from 2.0 to 5.0 at 4 degrees and 30 degrees C . At pH 10.0 it was completely inactivated . When submitted to 30 min at 80 degrees, 100 degrees and 115 degrees C, maximal stability was observed at pH 2.0 . Ethanol up to 10% did not affect pediocin activity at acid pH, nor did 40-80 mg 1-1 SO2, independently or combined with different ethanol concentrations, affect inhibitory activity. Biochemistry, 1995 Feb 28, 34(8), 2464 - 70 UDP-N-acetylmuramyl-L-alanine functions as an activator in the regulation of the Escherichia coli glutamate racemase activity; Ho HT et al.; D-Glutamate is an essential component of the bacterial peptidoglycan . In Escherichia coli, the biosynthesis of D-glutamate is catalyzed by a glutamate racemase (encoded by the dga gene) and is regulated by UDP-N-acetylmuramyl-L-alanine {Doublet et al . (1994) Biochemistry 33, 5285}, a bacterial peptidoglycan subunit precursor . Investigation was conducted to elucidate the interaction between the enzyme and its regulator . Whole and N-terminal truncated enzymes, encoded by individual constructs containing either a full-length or an N-terminal truncated dga gene, were evaluated . In the absence of the regulator, the purified whole enzyme showed a low-level basal racemase activity for which a Km value of 18.9 mM and a Vmax of 0.4 mumol/(min.mg) were determined, using D-glutamate as the substrate . Using the same substrate, in the presence of 6.5 microM UDP-N-acetylmuramyl-L-alanine, a Km value of 4.2 mM and a Vmax of 34 mumol/(min.mg) were measured . Similar kinetic parameters for the activated enzyme were obtained using L-glutamate as the substrate . The N-terminal truncated E . coli enzyme, with a 21 amino acid region removed, is similar in size to the Pediococcus pentosaceus glutamate racemase . Effects of the regulator on the full-length and the N-terminal truncated enzyme in the dialyzed cell lysate were compared . A host cell line, E . coli WM335 delta recA, containing a nonfunctional chromosomal dga gene was used to minimize the background interference . With 6.5 microM regulator added, the N-terminal truncated enzyme displayed a loss of more than 80% of the activity compared to the full-length enzyme.(ABSTRACT TRUNCATED AT 250 WORDS) J Bacteriol, 1995 Jan, 177(2), 336 - 42 Staphylococcus haemolyticus contains two D-glutamic acid biosynthetic activities, a glutamate racemase and a D-amino acid transaminase; Pucci MJ et al.; Two D-glutamic acid biosynthetic activities, glutamate racemase and D-amino acid transaminase, have been described previously for bacteria . To date, no bacterial species has been reported to possess both activities . Genetic complementation studies using Escherichia coli WM335, a D-glutamic acid auxotroph, and cloned chromosomal DNA fragments from Staphylococcus haemolyticus revealed two distinct DNA fragments containing open reading frames which, when present, allowed growth on medium without exogenous D-glutamic acid . Amino acid sequences of the two open reading frames derived from the DNA nucleotide sequences indicated extensive identity with the amino acid sequence of Pediococcus pentosaceous glutamate racemase in one case and with that of the D-amino acid transaminase of Bacillus spp . in the second case . Enzymatic assays of lysates of E . coli WM335 strains containing either the cloned staphylococcal racemase or transminase verified the identities of these activities . Subsequent DNA hybridization experiments indicated that Staphylococcus aureus, in addition to S . haemolyticus, contained homologous chromosomal DNA for each of these genes . These data suggest that S . haemolyticus, and probably S . aureus, contains genes for two D-glutamic acid biosynthetic activities, a glutamate racemase (dga gene) and a D-amino acid transaminase (dat gene). Microbios, 1995, 81(327), 115 - 22 Microflora of murcha: an amylolytic fermentation starter; Tamang JP et al.; Murcha is a traditional starter, used commonly in Darjeeling hills and Sikkim in India to ferment a variety of starchy substrates in order to produce sweet-sour alcoholic beverages, called jnards . Murcha cakes are mildly acidic (pH 5.2) and contain 13% w/w moisture and 0.7% w/w ash (dry weight basis) . A total of 194 bacterial, 190 yeast and 80 mould strains were isolated from 30 samples of murcha . The counts (cfu/g fresh weight) of micro-organisms in the samples were 2.0 x 10(7) to 4.2 x 10(8) for Pediococcus pentosaceus, 4.0 x 10(7) to 6.8 x 10(8) for Saccharomycopsis fibuligera, 2.0 x 10(6) to 7.2 x 10(7) for Pichia anomala, 1.0 x 10(6) to 4.1 x 10(7) for Mucor circinelloides and < 10 to 1.0 x 10(6) for Rhizopus chinensis . While all the species were prevalent in 100% of the samples, R . chinensis was detected in only 50% of them . Both the moulds but one yeast species, S . fibuligera had amylolytic activity. J Appl Bacteriol, 1994 Dec, 77(6), 682 - 8 Simple method of purification and sequencing of a bacteriocin produced by Pediococcus acidilactici UL5; Daba H et al.; A bacteriocin produced by a strain of Pediococcus acidilactici was successfully purified sequentially by acid extraction (at pH 2) and reverse-phase high-performance liquid chromatography (HPLC) . Cell extracts of derivative strains deficient in bacteriocin production exhibited a similar HPLC elution profile to the active extracts except for the two peaks containing bacteriocin activity . The sequence of the antibacterial peptide consisted of 44 amino acid residues of which 42 were identified, and its molecular weight was 4624 Da, as determined by mass spectrometry . Moreover, according to the molecular weight of the peptide, the unidentified residues in the bacteriocin sequence must correspond to two tryptophan residues, confirming that the peptide isolated from Ped . acidilactici UL5 is pediocin PA-1 . However, oxidized forms of the bacteriocin produced during storage also showed bacteriocin activity and resulted in a second peak with activity in the chromatograms . HPLC chromatograms of cell surface preparations from the active and from the deficient strains were confirmed by capillary electrophoresis . The purification method used is simple and effective in comparison with traditional methods, permitting a selective recovery of cell-associated bacteriocin at low pH, and its isolation in pure form for sequencing. Proc Natl Acad Sci U S A, 1994 Oct 11, 91(21), 10144 - 7 Bacterial glutamate racemase has high sequence similarity with myoglobins and forms an equimolar inactive complex with hemin; Choi SY et al.; Glutamate racemase (EC 5.1.1.3), an enzyme of microbial origin, shows significant sequence homology with mammalian myoglobins, in particular in the regions corresponding to the E and F helices, which constitute the heme binding pocket of myoglobins . Glutamate racemase binds tightly an equimolar amount of hemin, leading to loss of racemase activity . Although this enzyme shows homology with aspartate racemase, the latter does not bind hemin . The glutamate racemase gene of Pediococcus pentosaceus has a 795-nt open reading frame and encodes 265-amino acid residues, which form a monomeric protein (M(r) 29,000) . Neither racemase has cofactors, but they contain essential cysteine residues {Yohda, M., Okada, H . & Kumagai, H . (1991) Biochim . Biophys . Acta 1089, 234-240}. Appl Environ Microbiol, 1994 Sep, 60(9), 3405 - 8 Analysis of the pediocin AcH gene cluster from plasmid pSMB74 and its expression in a pediocin-negative Pediococcus acidilactici strain; Bukhtiyarova M et al.; The 3,500-bp pap operon in the 8,877-bp plasmid pSMB74 contains a cluster of four genes, papABCD, of which papA encodes prepediocin (A . M . Motlagh, M . Bukhtiyarova, and B . Ray, Lett . Appl . Microbiol . 18:305-312, 1994) . The cluster without the promoter was cloned in the shuttle vector pHPS9 . An Escherichia coli strain and a pediocin-sensitive Pediococcus acidilactici strain transformed with the recombinant plasmid, pMBR1.0, produced pediocin AcH . Deletion analysis by introducing mutations in the four genes in pMBR1.0 revealed that only papA and papD were required for pediocin AcH production and that the gene product of papD has both translocation and processing functions . In the transformed minicells of E . coli chi 925 the proteins of the pap cluster were synthesized, indicating no polar effect due to deletion. Lett Appl Microbiol, 1994 Jun, 18(6), 305 - 12 Complete nucleotide sequence of pSMB 74, a plasmid encoding the production of pediocin AcH in Pediococcus acidilactici; Motlagh A et al.; Several Pediococcus acidilactici strains produce a plasmid-encoded bacteriocin, pediocin AcH . Previous studies have shown that this plasmid, designated as pSMB 74, encodes genes associated with the production of prepediocin, its post-translation processing to pediocin AcH, transmembrane translocation of these molecules, and immunity of producer cells against pediocin AcH . We report here the complete nucleotide sequence of pSMB 74 . The plasmid has a total of 8877 bp . Four genes have been located on pSMB 74 . The genes are arranged in a gene cluster of 3500 bp and share a common promoter and rho-independent stem-loop terminator . The four genes, each with independent ribosome binding sites (rbs), initiation and termination codons and spacer sequences in between, were designated as pap A, pap B, pap C and pap D and encode respectively for proteins of 62, 112, 174 and 724 amino acids . The results of this study can be useful either to introduce a suitable marker at a unique restriction site in pSMB 74 and use it as a vector or to clone the pap gene cluster in a suitable plasmid and transform desirable strains for pediocin AcH production . The gene sequence has been submitted to Gene Bank (Acc . No . U02482). J Bacteriol, 1994 Jan, 176(2), 528 - 30 The Escherichia coli Dga (MurI) protein shares biological activity and structural domains with the Pediococcus pentosaceus glutamate racemase; Pucci MJ et al.; The Pediococcus pentosaceus glutamate racemase gene product complemented the D-glutamate auxotrophy of Escherichia coli WM335 . Amino acid sequence analysis of the two proteins revealed 28% identity, primarily in six clusters scattered throughout the sequence . Further analyses indicated secondary structure similarities between the two proteins . These data support a recent report that the dga (murI) gene product is a glutamate racemase. Appl Environ Microbiol, 1993 Nov, 59(11), 3577 - 84 Pediocin PA-1, a bacteriocin from Pediococcus acidilactici PAC1.0, forms hydrophilic pores in the cytoplasmic membrane of target cells; Chikindas ML et al.; Pediocin PA-1 is a bacteriocin which is produced by Pediococcus acidilactici PAC1.0 . We demonstrate that pediocin PA-1 kills sensitive Pediococcus cells and acts on the cytoplasmic membrane . In contrast to its lack of impact on immune cells, pediocin PA-1 dissipates the transmembrane electrical potential and inhibits amino acid transport in sensitive cells . Pediocin interferes with the uptake of amino acids by cytoplasmic membrane vesicles derived from sensitive cells, while it is less effective with membranes derived from immune cells . In liposomes fused with membrane vesicles derived from both sensitive and immune cells, pediocin PA-1 elicits an efflux of small ions and, at higher concentrations, an efflux of molecules having molecular weights of up to 9,400 . Our data suggest that pediocin PA-1 functions in a voltage-independent manner but requires a specific protein in the target membrane. Poult Sci, 1993 Sep, 72(9), 1772 - 8 Fate of Listeria monocytogenes and pediococcal starter cultures during the manufacture of chicken summer sausage; Baccus-Taylor G et al.; Two formulations of chicken summer sausages {100% hand deboned chicken meat (HDCM) and 85% HDCM and 15% chicken hearts (HDCM-CH)} were prepared with a nonpediocin-producing (PED-) Pediococcus acidilactici starter culture and inoculated with 10(4) or 10(7) cfu of a five-strain mixture of Listeria monocytogenes/g of batter . Sausages were fermented to pH 5.0 (11 h), cooked to an internal temperature of 66.5 C, cold-showered, and stored at 4 C (60 days) and 30 C (7 days) . For both formulations and inoculation levels, L . monocytogenes populations decreased 1.3 to 1.8 log10 cfu/g by the end of fermentation . No L . monocytogenes organisms were recovered from sausages (by enrichment) following the cook and shower or storage at 4 or 30 C . In contrast, P . acidilactici increased .7 to 1.2 log10 cfu/g during fermentation, and < 10(2) cfu/g remained after the cook and shower and storage at 4 and 30 C . In a second set of experiments, sausages (HDCM) were prepared with a PED- or a pediocin-producing (PED+) P . acidilactici starter culture and challenged with the L . monocytogenes mixture (10(7) cfu/g) . The PED- culture reduced numbers of L . monocytogenes 1.2 log10 cfu/g during fermentation, whereas L . monocytogenes numbers declined 2.6 log10 cfu/g in the presence of the PED+ culture . Although acid production by both starter cultures was equivalent, greater inhibition of L . monocytogenes by the PED+ compared with the PED- starter culture was attributed to in situ production of pediocin . Pediococcal starter cultures and proper cooking eliminated L . monocytogenes from sausages and established that PED+ cultures provide an additional hurdle against poultry-related listeriosis. Antimicrob Agents Chemother, 1993 Apr, 37(4), 789 - 92 Antimicrobial susceptibility of Pediococcus spp . and genetic basis of macrolide resistance in Pediococcus acidilactici HM3020; Tankovic J et al.; We determined the MICs of 28 antimicrobial agents against 36 clinical strains of Pediococcus spp . (25 P . acidilactici, 9 P . pentosaceus, and 2 P . urinaeequi strains) . Penicillin G, imipenem, gentamicin, netilmicin, erythromycin, clindamycin, rifampin, chloramphenicol, daptomycin, and ramoplanin were the most active . All strains of P . acidilactici were susceptible to novobiocin, whereas all isolates of P . pentosaceus were resistant . Novobiocin could therefore be helpful for differentiation of these two closely related species . P . acidilactici HM3020 was inducibly resistant to macrolide, lincosamide, and streptogramin B-type (MLS) antibiotics . Resistance was due to a determinant homologous to ermAM and carried by a nontransferable 46-kb plasmid, pVM20 . This plasmid was structurally distinct from two enterococcal MLS resistance plasmids, pIP819 and pAM beta 1 . The 34 strains of P . acidilactici and P . pentosaceus were resistant to tetracycline, and total DNA of these strains did not hybridize to probes specific for tetK, tetL, tetM, and tetO. J Appl Bacteriol, 1993 Apr, 74(4), 406 - 10 Characterization of bacteriocin produced by Pediococcus pentosaceus from wine; Strasser de Saad AM et al.; Twenty strains of Pediococcus pentosaceus isolated from wine were examined for production of bacteriocins . Only two of them showed inhibitory activity, Ped . pentosaceus N4p against the indicator strains of the same species and N5p against 19 strains of the three genera of lactic acid bacteria from wine . The antimicrobial substance from N5p strains was removed by membrane (0.2 micron) filtration, destroyed by organic solvents and proteolytic enzymes . It was stable for 60 min at 100 degrees C . The bacteriocin was produced early in the growth cycle and its production was maximum after 48 h of culture in tomato juice medium at an initial pH of 6.5 . The bactericidal effect was observed. Arch Biochem Biophys, 1993 Jan, 300(1), 364 - 71 Role of flavin in acetoin production by two bacterial pyruvate oxidases; Bertagnolli BL et al.; Escherichia coli pyruvate oxidase (POXEC) requires FAD both for the oxidative decarboxylation of pyruvate to acetate and CO2 and for the formation of acetoin from pyruvate and acetaldehyde . Prior work has shown that the catalytic activity (kcat/Km) for POXEC in the oxidative reaction is stimulated approximately 450-fold by amphiphilic activators . This paper shows that the acetoin reaction does not respond to activation . The FAD requirement for acetoin formation can be replaced by 5-deaza-FAD and 6-hydroxy-FAD, FAD analogs which form kinetically stable oxidized and reduced enzyme species, respectively . As would be expected, the 5-deaza- and 6-hydroxy-FAD enzymes are not active in the oxidative reaction . A second flavin pyruvate oxidase from Pediococcus pseudomonas (POXPP), which catalyzes the oxidative decarboxylation of pyruvate to CO2 and acetyl phosphate, also requires FAD for acetoin formation . POXPP has an oxidative rate comparable to that of POXEC, but in comparison to POXEC, POXPP catalyzes acetoin formation at a much reduced rate . Again, as was found with the POXEC, an FAD analog incapable of undergoing facile oxidation-reduction reactions also could replace the FAD requirement in the POXPP acetoin reaction . The results indicate that the role for FAD in acetoin formation with both enzymes is based on a structural requirement and that FAD does not participate in a redox function in the acetoin reaction. Ann Oncol, 1993, 4 Suppl 2, 1 - 5 Pharmacokinetics and in vitro studies of l-leucovorin . Comparison with the d and d,l-leucovorin; Zittoun J; BACKGROUND: The active isomer of leucovorin (LV), LV-6S was compared with the racemic form, LV-6R,S and the inactive form, LV-6R . MATERIALS AND METHODS: Pharmacokinetic studies of LV-6S and 6R,S were performed on normal volunteers and patients . Growth of Pediococcus Cerevisiae (PC), a LV-dependent strain, was measured with the 3 forms of LV . CCRF-CEM, a leukemic human cell line, was used to compare the effect of LV-6S, 6R,S and 6R on the rescue of methotrexate (MTX) and on the cytotoxicity of 5-fluorouracil (5-FU) . RESULTS: LV-6S exhibits pharmacokinetic patterns similar to those obtained with LV-6R,S whatever the route used, oral or intravenous . The growth of PC was similar with the active isomer and the racemic form while the unnatural isomer, LV-6R did not promote any growth . Cells exposed to MTX (10(-7) to 10(-5) M) were rescued from MTX cytotoxicity with LV-6S and LV-6R,S at concentrations 100 and 200 fold higher, whereas LV-6R did not reverse toxic effects of MTX . An enhancement of the cytotoxicity induced by 5-FU (10(-4) M) was obtained after preexposure of cells to LV-6S or LV-6R,S while LV-6R did not exhibit any synergistic effect . CONCLUSION: LV-6S has similar effects to LV-6R,S in vitro and in vivo but at half doses; its clinical use prevents the possible interference of the inactive isomer, especially in patients receiving high doses of LV. Appl Environ Microbiol, 1992 Oct, 58(10), 3312 - 5 Collapse of the proton motive force in Listeria monocytogenes caused by a bacteriocin produced by Pediococcus acidilactici; Christensen DP et al.; The effect of pediocin JD, a bacteriocin produced by Pediococcus acidilactici JD1-23, on the proton motive force and proton permeability of resting whole cells of Listeria monocytogenes Scott A was determined . Control cells, treated with trypsin-inactivated bacteriocin at a pH of 5.3 to 6.1, maintained a pH gradient and a membrane potential of approximately 0.65 pH unit and 75 mV, respectively . However, these gradients were rapidly dissipated in cells after exposure to pediocin JD, even though no cell lysis had occurred . The pH gradient and membrane potential of the producer cells were also unaffected by the bacteriocin . Whole cells treated with bacteriocin were twice as permeable to protons as control cells were . The results suggest that the inhibitory action of pediocin JD against L . monocytogenes is directed at the cytoplasmic membrane and that inhibition of L . monocytogenes may be caused by the collapse of one or both of the individual components of the proton motive force. Appl Environ Microbiol, 1992 Sep, 58(9), 3053 - 9 Genomic analysis of Pediococcus starter cultures used to control Listeria monocytogenes in turkey summer sausage; Luchansky JB et al.; The pulsed-field technique of clamped homogeneous electric field electrophoresis was employed to characterize and size genomic DNA of three pediocin-producing (Ped+) and two non-pediocin-producing (Ped-) strains of Pediococcus acidilactici . Comparison of genomic fingerprints obtained by digestion with the low-frequency-cleavage endonuclease AscI revealed identical restriction profiles for four of the five strains analyzed . Summation of results for 10 individually sized AscI fragments estimated the genome length to be 1,861 kb for the four strains (H, PAC1.0, PO2, and JBL1350) with identical fingerprints . Genomic analysis of the pediocin-sensitive, plasmid-free strain P . acidilactici LB42 with the unique fingerprint revealed nine AscI fragments and a genome length of about 2,133 kb . Ped- (JBL1350) and Ped+ (JBL1095) starter cultures (one each) were used to separately prepare turkey summer sausage coinoculated with a four-strain Listeria monocytogenes mixture (ca . 10(5) CFU/g) . The starter cultures produced equivalent amounts of acid during fermentation, but counts of L . monocytogenes were reduced to a greater extent in the presence of the Ped+ starter culture (3.4 log10 unit decrease) than in the presence of the Ped- starter culture (0.9 log10 unit decrease) . Although no listeriae were recovered from sausages following the cook/shower, appreciable pediocin activity was recovered from sausages prepared with the Ped+ strain for at least 60 days during storage at 4 degrees C . The results of this study revealed genomic similarities among pediococcal starter cultures and established that pediocins produced during fermentation provide an additional measure of safety against listerial proliferation in turkey summer sausage. Appl Environ Microbiol, 1992 Aug, 58(8), 2360 - 7 Cloning, expression, and nucleotide sequence of genes involved in production of pediocin PA-1, and bacteriocin from Pediococcus acidilactici PAC1.0; Marugg JD et al.; The production of pediocin PA-1, a small heat-stable bacteriocin, is associated with the presence of the 9.4-kbp plasmid pSRQ11 in Pediococcus acidilactici PAC1.0 . It was shown by subcloning of pSRQ11 in Escherichia coli cloning vectors that pediocin PA-1 is produced and, most probably, secreted by E . coli cells . Deletion analysis showed that a 5.6-kbp SalI-EcoRI fragment derived from pSRQ11 is required for pediocin PA-1 production . Nucleotide sequence analysis of this 5.6-kbp fragment indicated the presence of four clustered open reading frames (pedA, pedB, pedC, and pedD) . The pedA gene encodes a 62-amino-acid precursor of pediocin PA-1, as the predicted amino acid residues 19 to 62 correspond entirely to the amino acid sequence of the purified pediocin PA-1 . Introduction of a mutation in pedA resulted in a complete loss of pediocin production . The pedB and pedC genes, encoding proteins of 112 and 174 amino acid residues, respectively, are located directly downstream of the pediocin structural gene . Functions could not be assigned to their gene products; mutation analysis showed that the PedB protein is not involved in pediocin PA-1 production . The mutation analysis further revealed that the fourth gene, pedD, specifying a relatively large protein of 724 amino acids, is required for pediocin PA-1 production in E . coli . The predicted pedD protein shows strong similarities to several ATP-dependent transport proteins, including the E . coli hemolysin secretion protein HlyB and the ComA protein, which is required for competence induction for genetic transformation in Streptococcus pneumoniae.(ABSTRACT TRUNCATED AT 250 WORDS) Lett Appl Microbiol, 1992 Aug, 15(2), 45 - 8 Nucleotide and amino acid sequence of pap-gene (pediocin AcH production) in Pediococcus acidilactici H; Motlagh AM et al.; N-terminal analysis of purified pediocin AcH produced a partial sequence of 23 amino acids . This sequence matched perfectly with a segment of 23 amino acids in a 62 amino acid molecule generated from the 186 nucleotide sequence open reading frame in a Hind III fragment in pSMB74 encoding pap-gene (pediocin AcH production) . It is suggested that the molecule is translated as inactive prepediocin AcH of 62 amino acids . Then through enzymatic modifications the leader segment of 18 amino acids is removed from the NH2-terminal . The remaining segment of 44 amino acids is active pediocin AcH of 4628 M(r). Eur J Clin Microbiol Infect Dis, 1992 Jul, 11(7), 623 - 5 Septicemia and hepatic abscess caused by Pediococcus acidilactici; Sire JM et al.; A case of postoperative Pediococcus acidilactici septicemia with parallel isolation of the organism from hepatic specimens is presented . Laboratory methods to identify this vancomycin-resistant gram-positive cocci are described . Very few cases of documented infections due to this bacterium have been reported in the literature. J Biochem (Tokyo), 1992 Jul, 112(1), 139 - 42 Reaction mechanism of glutamate racemase, a pyridoxal phosphate-independent amino acid racemase; Choi SY et al.; Glutamate racemase of Pediococcus pentosaceus contained no cofactor, and was completely inactivated by a thiol reagent . The role of a cysteine residue in the enzyme reaction was studied by chemical modification . The modification of this cysteine residue resulted in a concomitant loss of activity . DL-Glutamate protected the enzyme from inactivation . The inactivated enzyme was reactivated by addition of dithiothreitol . The racemization in 2H2O showed an overshoot in the optical rotation of glutamate before the substrate was completely racemized . This indicates that the removal of alpha-hydrogen is the rate determining step . During the racemization of D- or L-glutamate in 3H2O, tritium was incorporated preferentially into the product . Glutamate is racemized by the enzyme probably through a two base mechanism. Arch Biochem Biophys, 1992 May 15, 295(1), 5 - 12 Purification and primary structure of pediocin PA-1 produced by Pediococcus acidilactici PAC-1.0; Henderson JT et al.; The plasmid-encoded bacteriocin pediocin PA-1, produced by the gram-positive bacterium Pediococcus acidilactici strain PAC-1.0, was purified to homogeneity . The purified product exhibited antibacterial activity against several gram-positive bacterial strains, including the food pathogen Listeria monocytogenes . Pediocin PA-1 is a 4629-Da peptide with 44 amino acids and two disulfide bonds . The amino acid sequence and arrangement of the disulfide bonds were determined . Sequence data were used to calculate an isoelectric point of 10.0 . The small and basic nature of PA-1 is comparable to several other bacteriocins produced by gram-positive bacteria . Reported sequences of other bacteriocins and of other antimicrobial peptides from diverse origins bear no resemblance to the sequence reported here. Appl Environ Microbiol, 1992 Mar, 58(3), 884 - 90 Enhanced control of Listeria monocytogenes by in situ-produced pediocin during dry fermented sausage production; Foegeding PM et al.; To determine whether pediocin is produced and has effective antilisterial activity during food fermentation, six sausage fermentation trials were conducted with antibiotic-resistant, pediocin-producing (Bac+) Pediococcus acidilactici PAC 1.0 (Strr Rifr) and an isogenic pediocin-negative (Bac-) derivative used as a control . Meat was inoculated (ca . 10(5) CFU/g) with a composite of five Listeria monocytogenes strains, each electrotransformed with pGK12 (Cmr Emr) . P . acidilactici and L . monocytogenes populations were selectively enumerated by plating on media with antibiotics . This study indicated that the dry sausage fermentation process can reduce L . monocytogenes populations . Effective inactivation of L . monocytogenes was observed when the pH at the end of the fermentation portion of the process was less than 4.9 . Pediocin was responsible for part of the antilisterial activity during the fermentation in each of the six trials . Furthermore, inhibition of L . monocytogenes during drying was enhanced in the presence of pediocin in the three trials in which L . monocytogenes could be detected throughout the drying process . Thus, pediocin production contributed to an increase in safety during both the fermentation and drying portions of sausage manufacturing. Appl Environ Microbiol, 1992 Feb, 58(2), 713 - 6 Detection of Pediococcus spp . in brewing yeast by a rapid immunoassay; Whiting M et al.; A membrane immunofluorescent-antibody test was developed to detect diacetyl-producing Pediococcus contaminants in brewery pitching yeast (yeast {Saccharomyces cerevisiae} slurry collected for reinoculation) . Centrifugations at 11 and 5,100 x g separate yeast cells from bacteria and concentrate the bacteria, respectively . Pelleted bacteria resuspended and trapped on a black membrane filter are reacted with monoclonal antibodies specific for cell surface antigens and then with fluorescein-conjugated indicator antibodies . Whether pitching yeast is contaminated with pediococci at 0.001% is determined in less than 4 h . The sensitivity of the assay is 2 orders of magnitude below the Pediococcus detection limit of direct microscopy. J Infect, 1991 Sep, 23(2), 179 - 82 Septicaemia caused by Pediococcus pentosaceus: a new opportunistic pathogen; Corcoran GD et al.; A case of septicaemia caused by Pediococcus pentosaceus is described . The role played by pediococci, and other vancomycin-resistant Gram-positive cocci, in disease states is examined . We suggest that in immunocompromised patients these organisms act as opportunist pathogens . This would appear to be the first reported case of P . pentosaceus septicaemia. Appl Environ Microbiol, 1991 May, 57(5), 1461 - 7 Behavior of Listeria monocytogenes in wiener exudates in the presence of Pediococcus acidilactici H or pediocin AcH during storage at 4 or 25 degrees C; Yousef AE et al.; Exudative fluids were collected from packages of five brands of all-beef wieners and inoculated to contain 10(4) to 10(5) CFU of a three-strain (Scott A, V7, and 101M) mixture of Listeria monocytogenes per ml . Listeriae were inactivated (decrease of 0.61 to 3.8 log10 CFU/ml) in all five exudates held at 4 degrees C for 29 days . L . monocytogenes grew (increase of 1.7 to 3.6 log10 CFU/ml) in two of five exudates held at 25 degrees C for 6 days . Exudate was inoculated with a derivative of Pediococcus acidilactici H (designated JBL1095) or treated with pediocin AcH (a bacteriocin) as a novel approach to control the growth of L . monocytogenes in wiener exudates . Initially, pediocin AcH caused rapid death (decrease of 0.74 log10 CFU/ml in 2 h) of L . monocytogenes in exudate held at 4 degrees C, but thereafter the inactivation was similar to that in control exudate (L . monocytogenes only) or exudate containing L . monocytogenes plus JBL1095 . At 25 degrees C, L . monocytogenes grew in the presence of JBL1095 during the first 64 h of incubation, but thereafter the numbers of the pathogen decreased appreciably (5.84 log10 CFU/ml in 3 days) . In the presence of pediocin AcH, there was a gradual decrease in numbers of L . monocytogenes throughout the storage period at 25 degrees C . These data indicate that added biopreservatives can potentiate and amplify the intrinsic listeriostatic or listericidal activity of wiener exudate. Protein Expr Purif, 1991 Feb, 2(1), 90 - 3 Overproduction of glutamate racemase of Pediococcus pentosaceus in Escherichia coli clone cells and its purification; Choi SY et al.; We previously isolated a 6.0-kb DNA fragment that specifies glutamate racemase activity from the chromosomal DNA of Pediococcus pentosaceus by digestion with HindIII (N . Nakajima, K . Tanizawa, H . Tanaka, and K . Soda, 1986), Agric . Biol . Chem . 50, 2823-2830) . We digested it further with EcoRI to obtain a fragment of 1.8 kb, which was blunt-ended and ligated into the SmaI site of vector plasmid pKK223-3 . The recombinant plasmid showed a high glutamate racemase activity upon transformation of Escherichia coli W3110 cells with it; the plasmid was named pICR223 . Glutamate racemase was overproduced in the clone cells and occurred in inclusion bodies in the cells . The enzyme was solubilized with 6 M urea, renatured by dialysis to remove urea, and purified to homogeneity with an overall yield of about 70% after a single DEAE-cellulose column chromatography . The amount of enzyme produced by the clone cells corresponded to about 38% of the total insoluble protein. J Appl Bacteriol, 1990 Aug, 69(2), 211 - 5 Antigenic property of pediocin AcH produced by Pediococcus acidilactici H; Bhunia AK et al.; Pediocin AcH, a bacteriocin of Pediococcus acidilactici H, inhibits the growth of several food spoilage and pathogenic bacteria . The antigenic property of partially purified pediocin AcH was tested by immunizing mice and a rabbit . Pediocin AcH was not immunogenic in these animals as determined by immunoblotting even after conjugation to bovine serum albumin . The non-immunogenic nature of pediocin AcH, its non-toxicity to laboratory animals and its hydrolysis by gastric proteolytic enzymes may be considered favourably in its possible use as a food preservative. Carbohydr Res, 1990 Aug 1, 203(1), 103 - 7 Structure of an exocellular beta-D-glucan from Pediococcus sp., a wine lactic bacteria; Llauberes RM et al.; Pediococcus sp . produces an exocellular slime containing exclusively D-glucose . The structure of the polysaccharide was determined by methylation analysis, Smith degradation, enzymic hydrolysis, and 13C-n.m.r . spectroscopy as having a trisaccharide repeating unit, ----3)-beta-D-Glcp-(1---- 3)-{beta-D-Glcp-(1----2)}-beta-D-Glcp-(1----. J Clin Microbiol, 1990 Jul, 28(7), 1678 - 9 Septicemia caused by vancomycin-resistant Pediococcus acidilactici; Golledge CL et al.; A case of septicemia caused by vancomycin-resistant Pediococcus acidilactici is discussed . This appears to be the first reported case of septicemia caused by this organism . The characteristics and antimicrobial susceptibilities of this organism are described. Appl Environ Microbiol, 1990 Jul, 56(7), 2142 - 5 Use of a bacteriocin produced by Pediococcus acidilactici to inhibit Listeria monocytogenes associated with fresh meat; Nielsen JW et al.; A bacteriocin produced by Pediococcus acidilactici had an inhibitory and bactericidal effect on Listeria monocytogenes associated with fresh meat . MICs were significantly lower than minimum killing concentrations . When meat was inoculated with L . monocytogenes, the bacteriocin reduced the number of attached bacteria in 2 min by 0.5 to 2.2 log cycles depending upon bacteriocin concentration . Meat treated initially with the bacteriocin resulted in attachment of 1.0 to 2.5 log cycles fewer bacteria than that attained with the control . The bacteriocin, after 28 days of refrigerated storage on meat surfaces, was stable and exhibited an inhibitory effect on L . monocytogenes. J Infect Dis, 1990 May, 161(5), 956 - 60 Vancomycin-resistant Pediococcus acidilactici: nine cases of bacteremia; Mastro TD et al.; Pediococci, vancomycin-resistant gram-positive cocci, have been isolated from human specimens, but an association with clinical illness has not been established . Clinical and epidemiologic data were obtained on nine patients who had Pediococcus acidilactici isolated from blood . Patients were eight elderly adults with complicated medical problems and one infant with congenital jejunoileal atresia . Seven patients were hospitalized before P . acidilactici was isolated . Eight had received multiple antibiotics; however, only two had received vancomycin . In all cases there was a delay in correct bacterial identification, and the significance of the isolate was uncertain . There was no clearly identified syndrome associated with P . acidilactici bacteremia . All eight adults had fever and six had pneumonia potentially attributable to other causes . The findings underscore the importance of proper identification of vancomycin-resistant gram-positive cocci . P . acidilactici may be an opportunistic pathogen in severely compromised hosts; however, further observations are necessary to clarify its role in human disease. Crit Rev Food Sci Nutr, 1990, 29(4), 237 - 53 Glycolysis and related reactions during cheese manufacture and ripening; Fox PF et al.; Fermentation of lactose to lactic acid by lactic acid bacteria is an essential primary reaction in the manufacture of all cheese varieties . The reduced pH of cheese curd, which reaches 4.5 to 5.2, depending on the variety, affects at least the following characteristics of curd and cheese: syneresis (and hence cheese composition), retention of calcium (which affects cheese texture), retention and activity of coagulant (which influences the extent and type of proteolysis during ripening), the growth of contaminating bacteria . Most (98%) of the lactose in milk is removed in the whey during cheesemaking, either as lactose or lactic acid . The residual lactose in cheese curd is metabolized during the early stages of ripening . During ripening lactic acid is also altered, mainly through the action of nonstarter bacteria . The principal changes are (1) conversion of L-lactate to D-lactate such that a racemic mixture exists in most cheeses at the end of ripening; (2) in Swiss-type cheeses, L-lactate is metabolized to propionate, acetate, and CO2, which are responsible for eye formation and contribute to typical flavor; (3) in surface mold, and probably in surface bacterially ripened cheese, lactate is metabolized to CO2 and H2O, which contributes to the increase in pH characteristic of such cheeses and that is responsible for textural changes, (4) in Cheddar and Dutch-type cheeses, some lactate may be oxidized to acetate by Pediococci . Cheese contains a low level of citrate, metabolism of which by Streptococcus diacetylactis leads to the production of diacetyl, which contributes to the flavor and is responsible for the limited eye formation characteristic of such cheeses. Appl Environ Microbiol, 1988 Oct, 54(10), 2349 - 53 Inhibition of Listeria monocytogenes by using bacteriocin PA-1 produced by Pediococcus acidilactici PAC 1.0; Pucci MJ et al.; The bacteriocin produced by Pediococcus acidilactici PAC 1.0, previously designated PA-1 bacteriocin, was found to be inhibitory and bactericidal for Listeria monocytogenes . A dried powder prepared from PAC 1.0 culture supernatant fortified with 10% milk powder was found to contain bacteriocin activity . An MIC against L . monocytogenes and lytic effects in broth cultures were determined . Inhibition by PA-1 powder occurred over the pH range 5.5 to 7.0 and at both 4 and 32 degrees C . In addition, inhibition of L . monocytogenes was demonstrated in several food systems including dressed cottage cheese, half-and-half cream, and cheese sauce. Br J Nutr, 1987 Nov, 58(3), 485 - 91 Tissue folates in fruit bats (Rousettus aegyptiacus) with nitrous oxide-induced vitamin B12 deficiency and neurological impairment; van der Westhuyzen J et al.; 1 . Long-term exposure of the fruit bat Rousettus aegyptiacus to nitrous oxide, which inactivates methylcobalamin, leads to neurological impairment and ataxia . 2 . In N2O-exposed animals, liver concentrations of total folates and methyl folates decreased to less than one-fifth that of control animals . Pediococcus cerevisiae-active folates were also reduced . 3 . In brain, there were no changes in total or methyl folates, but P . cerevisiae-active folates were lower in N2O-exposed animals . 4 . Supplementation with methionine retarded the development of neurological impairment and the fall in liver total and methyl folates, but not that in P . cerevisiae-active folates . 5 . Supplementation with serine failed to retard the development of neurological impairment or fall in hepatic folates . 6 . The present results suggest that the N2O-induced neurological impairment in the bat is not related to depletion of cerebral folates, but do not exclude changes in the subcellular distribution of folates. Biosensors, 1987-88, 3(4), 227 - 37 Enzyme electrode composed of the pyruvate oxidase from Pediococcus species coupled to an oxygen electrode for measurements of pyruvate in biological media; Zapata-Bacri AM et al.; Pyruvate oxidase from Pediococcus species was immobilized with gelatin and insolubilized in film form by tanning with glutaraldehyde . The film was fixed onto the tip of an oxygen electrode . The enzyme electrode was specific for pyruvate measurements . This electrode was sensitive to 0.1 mM and could be used up to a final pyruvate concentration of 2 mM . At each step of the enzymatic film preparation and assay 0.7 mM thiamine pyrophosphate, 10 microM flavin adenine dinucleotide, 5 mM Mg2+ and 10 mM phosphate buffer were necessary . A computerized probe allowed successive measurements every 3 min for more than 20 h with the same enzymatic film . The reproducibility for the same pyruvate concentration was 2% during 400 assays without special optimization . This enzyme electrode has many applications in basic (metabolism, enzymology) and applied (blood, yoghurt) research . Results obtained from assays carried out in yoghurt are presented. NCI Monogr, 1987, (5), 57 - 60 Bioavailability of high-dose oral leucovorin; Hines JD et al.; Fifteen adult subjects comprised the study group; 2 were colon cancer patients . Total leucovorin (citrovorum factor; CF) doses of 200, 400, 800, and 1600 mg were equally subdivided and administered at 0, 1, 2, and 3 hours . Three of the subjects were fasting and the other 12 were not . Quantitation of serum L-CF by Pediococcus cerevisiae and total reduced folates (TRF) by radio-assay were performed in 10 samples from each subject drawn over a 12-hour period after initiation of CF dosing . The mean serum levels of L-CF remained greater than 0.1 microM at 3 hours and the TRF 3.5 microM at 5 hours, respectively, after termination of CF dosing in all subjects treated at the 800- and 1600-mg dose schedule . At all CF dosage schedules employed, peak serum concentrations were reached within 4 and 6 hours after initiation of oral CF . Peak TRF concentrations at the 200-, 400-, 800-, and 1600-mg doses were 3.42 +/- 0.65, 4.05 +/- 1.04, 4.81 +/- 0.14, and 5.11 +/- 1.81 microM, respectively . Peak L-CF levels at 200, 400, 800, and 1600 were 0.15 +/- 0.11, 0.21 +/- 0.14, 0.23 +/- 0.11, and 0.34 +/- 0.16 microM . Based upon these observations, the following conclusions were reached: 1) no significant differences were observed in serum concentrations of folates between the 800- and 1600-mg dose schedules; 2) at these doses serum concentrations of L-CF and TRF were achieved that warrant a phase I investigation of high-dose oral CF with standard dose FUra in patients with advanced colorectal carcinoma. Crit Rev Microbiol, 1987, 14(4), 291 - 309 Pediococci and biotechnology; Raccach M; Nomenclature changes of pediococci postdate the publication of Bergey's Manual . Pediococci possess both a "group" and a "type" antigen . They are gram positive, asporogenous, nonmotile, generally catalase negative, but may possess catalase-like activity . The pediococci may have either a cytochrome or a flavoprotein enzyme system . Anaerobically they are homofermentative using the PEP:PTS and the EMP pathway . Catalase positive strains utilize glucose aerobically and anaerobically while lactose and glycerol are only used aerobically . Some pentoses are fermented to lactate and acetate . Absolute requirement for folinic acid and nearly all amino acids is observed . Pediococci grow luxuriously in All Purpose Tween (APT) broth and are isolated on Rogosa SL agar . Detection can be done by electrical impedance and fluorescent antibody techniques . The Arrhenius concept was utilized in selecting metabolically efficient strains . Antibiotics, antioxidants, some chloride salts and some spices are detrimental to the pediococci . On the other hand, some chloride salts, manganese, and some spices are stimulant . Dialysis-fermentation and immobilization of pediococcal cells were recorded . Some strains decarboxylate histidine to histamine . The resting cell metabolism and the production of bacteriocin have been utilized in antibiosis . An intra and intergeneric genetic transfer system of plasmids from pediococci was by a conjugation-like mechanism . Formation of bacteriocin and fermentation of carbohydrates were linked to plasmids . Lytic bacteriophages to pediococci have not yet been identified . Industrial cultures are mainly frozen concentrates . Linear equations were developed to model the fermentative activity of pediococci and the effects of environmental factors. J Histochem Cytochem, 1986 Jun, 34(6), 761 - 8 Direct measurement of femtogram amounts of DNA in cells and chloroplasts by quantitative microspectrofluorometry; Lawrence ME et al.; Absolute DNA amounts of individual chloroplasts were determined by measuring the fluorescence intensity of chloroplasts stained with 4',6-diamidino-2-phenylindole (DAPI) relative to that of the bacterium Pediococcus damnosus (cerevisiae) smeared on the same slide . An absolute DNA content of 7.7 X 10(15) g for a standard P . damnosus cell type was calculated by comparing the relative fluorescence values and frequency of each stage of cellular development in a culture to the average DNA content of all cell types determined by chemical methods . Chlorophyll was extracted from the chloroplasts during fixation so that chlorophyll autofluorescence was not present when DAPI fluorescence was measured . Absolute amounts of DNA could then be determined for single chloroplasts, either within cells that were individually selected from a mixed cell population or in small preparations of isolated chloroplasts . The DNA amounts of chloroplasts from mesophyll cells determined in this way were similar to the values previously determined by bulk averaging methods . Chloroplast DNA amounts from different cell types of the leaf could be measured by microspectrofluorometry, and it was found that chloroplasts from spinach epidermal cells contained about half as much DNA as chloroplasts from adjacent mesophyll cells. Appl Environ Microbiol, 1985 Apr, 49(4), 908 - 13 Lactate metabolism by pediococci isolated from cheese; Thomas TD et al.; Pediococcus pentosaceus is commonly found among the adventitious microflora of Cheddar cheese . When this organism was incubated with L-(+)-lactate under anaerobic conditions, L-(+)-lactate was rapidly converted to D-(-)-lactate until racemic (DL) lactate was present . Under aerobic conditions this initial reaction was followed by a slower reaction resulting in the use of both lactate isomers and in the production of acetate and CO2 . With intact cells the lactate oxidation system had an optimum pH of 5 to 6, depending on the initial lactate concentration . Cells grown anaerobically possessed lactate-oxidizing activity which increased two- to fourfold as sugar was exhausted from the medium . Aerobic growth further increased specific activities . Cheddar cheese was made with the deliberate addition of P . pentosaceus . When the resulting cheese was grated to expose a large surface area to O2, lactate was converted to acetate at a rate which depended on the density of pediococci in the cheese . The lactate oxidation system remained active in cheese which had been ripened for 6 months. Crit Care Med, 1984 May, 12(5), 461 - 4 Rapid micromeasurement of lactate in whole blood; Clark LC Jr et al.; A new lactate sensor makes it possible to measure the lactate content of whole blood directly in less than 1 min, using only a 10-microL blood sample . The procedure works equally well with plasma, serum, spinal fluid, other body fluids, or tissue homogenates . The instrument is calibrated with lactate standards between 0 and 15 mMol/L . The sensor, a polarographic enzyme electrode, gives a current which is a linear function of the lactate concentration . There is no interference from glucose, pyruvate, alcohol, ascorbate, anticoagulants, lidocaine, acetaminophen, or other drugs and metabolites commonly encountered in critically ill patients . The lactate sensor is composed of a peroxide sensor and an enzyme transducer membrane . The lactate is stoichiometrically converted to pyruvate and hydrogen peroxide by lactate oxygen oxidoreductase derived from Pediococcus species . The oxygen required for the enzymatic oxidation is supplied via an air-permeable silicone elastomeric membrane used for stirring . Comparison of our new electroenzymatic method with the Boehringer-Mannheim photoenzymatic method gives correlations of 0.997 for both whole blood and plasma. Br J Nutr, 1983 May, 49(3), 343 - 54 Storage of milk powders under adverse conditions . I . Losses of lysine and of other essential amino acids as determined by chemical and microbiological methods; Hurrell RF et al.; Whole-milk powders containing 25 g water/kg were stored for up to 9 weeks in sealed aluminium containers at elevated temperatures . Lysine and other essential amino acids were measured by chemical and microbiological methods . Storage at 60 degrees resulted in the progressive formation of lactulosyl-lysine . After 9 weeks, 30% of the lysine groups were present in this form . The powders still retained their natural colour and the levels of tryptophan, methionine, cyst(e)ine and leucine remained unchanged . Storage at 70 degrees resulted in the formation of lactulosyl-lysine followed by its complete degradation with the development of browning . Available tryptophan, methione, leucine and isoleucine decreased progressively during storage . The different methods for lysine determination gave widely dissimilar results . The direct fluorodinitrobenzene (FDNB) technique and reactive lysine from furosine were considered to be the most reliable methods . The FDNB-difference, dye-binding lysine, Tetrahymena and Pediococcus methods all seriously underestimated reactive or available lysine in heat-damaged milk powders . Tetrahymena and Pediococcus appeared to utilize lactulosyl-lysine as a source of lysine . The results are discussed in relation to storage and distribution of milk powders in hot climates. J Bacteriol, 1982 May, 150(2), 616 - 22 Physiological and enzymatic properties of a thymidine-requiring Pediococcus cerevisiae mutant; Ariel M et al.; We describe the isolation and characterization of a Pediococcus cerevisiae thymidine-requiring mutant and its thymidine-independent revertant . The mutant strain lacked thymidylate synthetase activity and had an absolute requirement for low concentrations (2 micrograms/ml) of thymidine in addition to a requirement for N-5-formyl tetrahydrofolic acid (folinate) . Even at high concentrations (up to 500 micrograms/ml), thymine could not replace thymidine . In contrast to its wild-type parent, which grows only on folinate, the thymidine-requiring mutant (Thy- Fol+) was able to take up and grow on picogram quantities of unreduced folic acid . When both strains were grown on folinate, the Thy- Fol+ strain was at least 10(3)-fold more resistant to the folic acid analogs aminopterin and methotrexate than the wild-type strain . On the other hand, when grown on folic acid, the Thy- Fol+ strain was as sensitive to the folic acid analogs as the Thy+ Fol+ strain and was 10(2)-fold more sensitive than the wild-type strain grown on folinate . The thymidine-independent revertant (Thy+ Fol+) regained the wild-type level of thymidylate synthetase activity, but maintained the ability to take up and grow on unreduced folic acid like its Thy- Fol+ parent. Acta Microbiol Pol, 1977, 26(1), 65 - 78 Aspartate aminotransferase of Pediococcus cerevisiae; Galas E et al.; A five-step procedure is described for preparing highly purified aspartate aminotransferase (L-aspartate: 2-oxoglutarate aminotransferase, EC.2.6.1.1) from cell-freee enzyme extracts of Pediococcus cerevisiae . An overall purification of 130-fold was achieved . Some of P . cerevisiae aspartate aminotransferase properties were studied, i.s . pH optimum (7.8--8.0), optimum of temperature (37 degrees), Michaelis constans for 4 enzyme substrates and substrate specificity of enzyme . The enzyme is very thermolabile . During purification the enzyme was stabilizated by 2-oxoglutarate . The highly purified preparation was stored in the solution containing ammonium sulphate . The obtained aspartate aminotransferase preparation was free of alanine and aromatic amino acids aminotransferase activites and did not reveal malate dehydrogenase activity. Biochim Biophys Acta, 1976 May 28, 428(3), 674 - 82 Resistance to Pediococcus cerevisiae to amethopterin as a consequence of changes in enzymatic activity and cell permeability . II . Permeability changes to amethopterin and other folates in the drug-resistant mutant; Mandelbaum-Shavit F; the accumulation of amethopterin in a Pediococcus cerevisiae strain resistant to this analogue was about 30% of that in P . cerevisiae/PteGlu, the sensitive parent . The uptake in the resistant strain was strictly glucose dependent, whereas in the sensitive parent about 16% accumulation occurred in absence of glucose . The transport in both strains was inhibited by iodoacetate and KF . Amethopterin uptake exhibited saturation kinetics with an apparent Km of 5 muM in P . cerevisiae/AMr and 0.5 muM in P . cerevisiae/PteGlu . The apparent V was 0.2 nmol per min per mg cells (dry weight); the same for both strains . The optimum pH for the uptake of amethopterin by P . cerevisiae/AMr and P . cerevisiae/PteGlu was pH 6.0 . Folate and methyltetrahydrofolate competitivity inhibited amethopterin uptake with apparent Ki values of 8 and 0.7 muM, respectively . The uptake of folate exhibited a slightly increased Km value as compared to that of the sensitive strain, whereas the uptake activity velocity was in the same range . Methyltetrahydrofolate accumulated up to about 60-fold higher intracellular concentration than that of the medium, which is a markedly lower accumulation from that in the sensitive strain . The uptake was glucose dependent and inhibited by iodoacetate and KF . The pH optimum for methyltetrahydrofolate uptake in the resistant strain was the same as that in the sensitive parent (pH 5.7--6) . In contrast to the increase in the apparent Km value for amethopterin in the resistant strain, the affinity of the carrier for methyltetrahydrofolate was apparently unchanged, whereas the V value was about 16 times lower than that in the sensitive strain . The Ki for amethopterin when added to increasing concentrations of methyltetrahydrofolate was 5.2 muM, a value about the same as that of the Km. Biochim Biophys Acta, 1976 May 28, 428(3), 664 - 73 Resistance of Pediococcus cerevisiae to amethopterin as a consequence of changes in enzymatic activity and cell permeability . I . Dihydrofolate reductase, thymidylate synthetase and formyltetrahydrofolate synthetase in amethopterin-resistant and -sensitive strains of Pediococcus cerevisiae; Mandelbaum-Shavit F; Pediococcus cerevisiae/AMr, resistant to amethopterin, possesses a higher dihydrofolate reductase (5, 6, 7, 8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) activity than the parent, a folate-permeable and thus amethopterin-susceptible strain and than the wild-type . The properties of dihydrofolate reductase from the three strains have been compared . Temperature, pH optima, heat stability, as well amethopterin binding did not reveal significant differences between the enzymes from the susceptible and resistant strains . The enzyme from the wild-type was 10 times more sensitive to inhibition by amethopterin and more susceptible to heat denaturation . The apparent Km values for dihydrofolate in enzymes from the three strains were in the range of 4.8--7.2 muM and for NADPH 6.5--8.0 muM . The amethopterin-resistant strain exhibited cross-resistance to trimethoprim and was about 40-fold more resistant to the latter than the sensitive parent and the wild-type . The resistance to trimethoprim appears to be a direct result of the increased dihydrofolate reductase activity . Inhibition of dihydrofolate reductase activity by this drug was similar in the three strains . 10--20 nmol caused 50% inhibition of 0.02 enzyme unit . Trimethoprim was about 10 000 times less effective inhibitor of dihydrofolate reductase than amethopterin . The cell extract of the AMr strain possessed a folate reductase activity three times higher than that of the sensitive strain . The activities of other folate-related enzymes like thymidylate synthetase and 10-formyltetrahydrofolate synthetase (formate: tetrahydrofolate ligase (ADP-forming), EC 6.3.4.3) were similar in the three strains studied. J Gen Microbiol, 1976 Jan, 92(1), 138 - 46 The nutritional requirements of methicillin-dependent and -resistant strains of Pediococcus cerevisiae; Widdowson D et al.; A new methicillin-dependent and -resistant substrain (called MRD) of Pediococcus cerevisiae was developed by serial passages followed by replica-plating . Other methicillin-resistant, but not -dependent, substrains were isolated after treatment of the same parent strain with a mutagen . A methicillin-independent partial revertant, still resistant to the drug, was isolated from the original methicillin-dependent and -resistant substrain (CRD) developed several years ago . The requirements of some of these strains for acetate, vitamins and amino acids were compared . All except the parent methicillin-sensitive strain required pantothenate for growth, but no other consistent differences were found . The parent, but not strain CRD, grew without lysine added to the medium, though 19 other amino acids were needed by each strain . Both of these strains fermented glucose to lactate (mainly the L-isomer) in the absence or presence of methicillin. Cancer Chemother Rep, 1975 Sep-Oct, 59(5), 935 - 7 Assay for citrovorum factor (NSC-3590) in the presence of methotrexate (NSC-740); Mehta BM et al.; Treatment of certain malignancies with high-dose methotrexate/citrovorum factor rescue has recently been adopted as an effective regimen . A microbiologic assay capable of detecting citrovorum factor in the presence of massive amounts of methotrexate has been developed using a strain of Pediococcus cerevisiae resistant to methotrexate . The assay described in this paper is an inexpensive and rapid method of studying the distribution kinetics of citrovorum factor. J Bacteriol, 1975 Aug, 123(2), 400 - 6 Pediococcus cerevisiae mutant with altered transport of folates; Mandelbaum-Shavit F et al.; A Pediococcus cerevisiae mutant that actively accumulated folate (PteGlu), in contrast to the wild-type, was also found to exhibit changes in the pattern of uptake of 5-methyl-tetrahydrofolate (5-CH3-H4PteGlu) and amethopterin . Most of the 5-CH3-H4PteGlue accumulated through a glucose- and temperature-dependent process, and a concentrative uptake was also found in gluocse-starved cells and in cells incubated at OC . About 75% of the accumulated 5-CH3-H4PteGlu exchanged with amethopterin . In contrast to the wild type, the mutant accumulated both diastereoisomers of 5-CH3-H4PteGlue by glucose-dependent and glucose-independent processes . Amethopterin and PteGlue competitively inhibited the uptake in both processes, with an apparent lower affinity of the carrier for PteGlu than for the analogue . p-Chloromercuribenzoate strongly inhibited the uptake (75%) . The p-chloromercuribenzoate-nonsusceptible and temperature-independent uptake was also competed by amethopterin . Metabolic poisons like sodium azide, potassium fluoride, iodoacetate, and 2,4-dimitrophenol inhibited the glucose-dependent process . Uptake, in the absence of glucose, was enhanced by sodium azide and potassium fluoride. J Bacteriol, 1975 Feb, 121(2), 600 - 7 Production of racemic lactic acid in Pediococcus cerevisiae cultures by two lactate dehydrogenases; Gordon GL et al.; Nicotinamide adenine dinucleotide (NAD)-dependent d(minus)-and l(plus)-lactate dehydrogenases have been partially purified 89- and 70-fold simultaneously from cell-free extracts of Pediococcus cerevisiae . Native molecular weights, as estimated from molecular sieve chromatography and electrophoresis in nondenaturing polyacrylamide gels, are 71,000 to 73,000 for d(minus)-lactate dehydrogenase and 136,000 to 139,000 for l(plus)-lactate dehydrogenase . Electrophoresis in sodium dodecyl sulfate-containing gels reveals subunits with approximate molecular weights of 37,000 to 39,000 for both enzymes . By lowering the pyruvate concentration from 5.0 to 0.5 mM, the pH optimum for pyruvate reduction by d(minus)-lactate dehydrogenase decreases from pH 8.0 to 3.6 . However, l(plus)-lactate dehydrogenase displays an optimum for pyruvate reduction between pH 4.5 and 6.0 regardless of the pyruvate concentration . The enzymes obey Michaelis-Menten kinetics for both pyruvate and reduced NAD at pH 5.4 and 7.4, with increased affinity for both substrates at the acid pH . alpha-Ketobutyrate can be used as a reducible substrate, whereas oxamate has no inhibitory effect on lactate oxidation by either enzyme . Adenosine triphosphate causes inhibition of both enzymes by competition with reduced NAD . Adenosine diphosphate is also inhibitory under the same conditions, whereas NAD acts as a product inhibitor . These results are discussed with relation to the lactate isomer production during the growth cycle of P . cerevisiae.
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