|
|
|
|
|
|
Technically, the 'coliform group' is defined to be all the aerobic and facultative anaerobic, non-spore-forming, Gram-negative, rod-shaped bacteria that ferment lactose with the production of gas within 48 hours at 35°C (in the body, this gas is released as flatulence). In the fields of water purification and sewage treatment, E. coli was chosen very early in the development of the technology as an 'indicator' of the pollution level of water, meaning the amount of human fecal matter in it. The main reasons for using E. coli are that there are a lot more coliforms in human feces than there are pathogens (such as Salmonella typhi, which causes typhoid), and E. coli is usually harmless, so it can't 'get loose' in the lab and hurt anyone. It can be misleading to use E. coli as an indicator of human fecal contamination because there are other environments in which E. coli grows well, such as paper mills. Agrobacterium tumefaciens is a species of bacteria that causes tumors (commonly known as 'galls' or 'crown galls') on a wide range of dicots. It does so by inserting a small segment of DNA (known as the T-DNA, for 'transfer DNA') into the plant cell. The T-DNA encodes genes for plant growth hormones, which cause the tumor, and genes for enzymes that create sugars which the bacteria can metabolize. The T-DNA inserts at a semi-random location in the host genome, and when the genes are expressed by the host, a tumor forms full of food for the bacteria. The DNA transmission capabilities of Agrobacterium have been extensively exploited in biotechnology as a means of inserting foreign genes into plants. The mechanism by which Agrobacterium inserts materials into the host cell is very similar to mechanisms used by human pathogens to insert materials (usually proteins) into human cells, making a Agrobacterium an important subject of medical research as well. Click on following items to see more information: Acinetobacter, Antibacterial, Antibiotic, Antibiotic, Antibacterial, Bacilli, Bacterium, Bacterium, Antibacterial, Phages, Biodegradation, Campylobacter, Cell culture, Ciprofloxacin, Corynebacteria, E. coli, E. coli, E. coli, E. coli, E. coli, E. coli, Erythromycin, Functional genomics, Yeast, Growth medium, Kluyveromyces, Meningococci, Bacterial, Micrococcus, Multidrug resistance, Pasteurella, Prokaryote, P. aeruginosa, Saccharomyces cerevisiae, Saccharomyces cerevisiae, Salmonella, Salmonella, Staphylococci, Staphylococci, Streptococcus, Streptococcus, Vibrio The sphingomonads are widely distributed in nature, having been isolated from many different land and water habitats, as well as from plant root systems, clinical specimens, and other sources. Some of the sphingomonads (especially Sphingomonas paucimobilis) also play a role in human disease, primarily by causing a range of mostly nosocomial, non-life-threatening infections that typically are easily treated by antibiotic therapy. Due to their biodegradative and biosynthetic capabilities, sphingomonads have been utilised for a wide range of biotechnological applications, from bioremediation of environmental contaminants to production of extracellular polymers such as sphingans used extensively in the food and other industries. Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. Bioremediation may be employed in order to attack specific contaminants, such as chlorinated pesticides that are degraded by bacteria, or a more general approach may be taken, such as oil spills that are broken down using multiple techniques including the addition of fertilizer to facilitate the decomposition of crude oil by bacteria.
|
© 2005
Transgalactic Ltd (manufacturer of Bioscreen C software) |
Privacy Statement | P.O. Box
1393, 00101 Helsinki, Finland,
Last modified: May 25, 2005
| ||||||
