Listeria innocua: Difference between revisions
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==Cell structure and metabolism== | ==Cell structure and metabolism== | ||
''Listeria innocua'' are Gram positive bacteria, meaning they have a thick cell wall for protection. The cell wall is studded with hydrophilic molecules such as teichoic acids to repel hydrophobic molecules such as drugs. These organisms also produce flagella and pili for motility. ''Listeria innocua'' have very complex metabolism. They are capable of metabolizing methane, sulfur and nitrogen, among many other organic and inorganic compounds. These organisms also carry out numerous biosynthetic pathways, including peptidoglycan synthesis. ''Listeria innocua'', like other members of their genus, are facultative anaerobes, which means that they can metabolism glucose (and other simple sugars) in under both aerobic and anaerobic conditions. Under the aerobic metabolism of glucose, ''L. innocua'' forms lactic acid and acetic acid. However, under anaerobic conditions, the metabolism of glucose yields only lactic acid. | |||
==Ecology== | ==Ecology== | ||
Revision as of 07:34, 30 April 2007
A Microbial Biorealm page on the genus Listeria innocua
Classification
Higher order taxa:
Bacteria; Firmicutes; Bacilli; Bacillales; Listeriaceae; Listeria
Species:
Listeria innocua
Description and significance
Listeria innocua is widely found in the environment (such as soil) and food sources. It can survive in extreme pH and temperature and high salt concentration. In terms of appearance, it is a rod-shaped Gram positive bacterium. It may live individually or organize into chains with other Listeria innocua bacteria. It is a mesophile, operating at an optimal temperature range of 30-37 degrees Celsius. Listeria innocua very much resembles its other family member, the pathogenic Listeria monocytogenes. Listeria innocua was isolated from meat by a technique called surface adhesion immunofluorescence. Samples of meat were inoculated with Listeria innocua and incuated at 30 degrees Celsium for 14-18 hours in a broth. The cells were then isolated from the meat by surface adhesion onto a polycarbonate membrane attached to a microscope glass slide. Then immunofluorescent microscopy was employed to visualize the bacteria. It is important because it was previously known for being non-pathogenic, but recently researchers found a case of Listeria innocua infection of an elderly patient.
Genome structure
Listeria innocua has a circular chromosome made up of 3,011,209 base pairs, with a 37% G+C content. Only 2,973 protein-coding genes were discovered in L. innocua, while no function could be predicted for 37% of the genes. The genome encodes a great variety of regulatory, surface and transport proteins. This explains why Listeria species can adapt to and inhabit such a wide range of environments. Listeria innocua was found to be deficient in a 10-kb virulence locus, a cluster of genes that engenders pathogenicity to Listeria monocytogenes. This explains why L. innocua typically does not infect humans or animals. It also has a circular plasmid of 81,905 base pairs whose function is unknown.
Cell structure and metabolism
Listeria innocua are Gram positive bacteria, meaning they have a thick cell wall for protection. The cell wall is studded with hydrophilic molecules such as teichoic acids to repel hydrophobic molecules such as drugs. These organisms also produce flagella and pili for motility. Listeria innocua have very complex metabolism. They are capable of metabolizing methane, sulfur and nitrogen, among many other organic and inorganic compounds. These organisms also carry out numerous biosynthetic pathways, including peptidoglycan synthesis. Listeria innocua, like other members of their genus, are facultative anaerobes, which means that they can metabolism glucose (and other simple sugars) in under both aerobic and anaerobic conditions. Under the aerobic metabolism of glucose, L. innocua forms lactic acid and acetic acid. However, under anaerobic conditions, the metabolism of glucose yields only lactic acid.
Ecology
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Enter summaries of the most recent research here--at least three required
References
Edited by student of Rachel Larsen and Kit Pogliano
