User:BottsE: Difference between revisions
Line 23: | Line 23: | ||
==Genome structure== | ==Genome structure== | ||
The circular genome of B. longum contains 2, 256, 656 base pairs, with 60% of them being G-C pairs. 86% of these genes are thought to be coding (1,730 coding regions), and 22% are specific to B. longum (unless they have yet to be identified in other species). The genome codes for 4 nearly identical rrn operons, 57 tRNAs that code for all 20 amino acids, and 16 intact insertion sequence elements (7). In terms of plasmids, they have been found in 70% of the sequenced B. longum strains, and 7 different types have been identified. Furthermore, some strains harbor defective lysogenic phages, which are dormant plasmids that still contain DNA (1). | |||
The sequence of B. longum subspecies infantis shows a large inverted region (about 1.3 Mb) in the middle of the genome compared to both B. longum strains. This inversion could possibly be a recent evolutionary event (6). | |||
==Cell structure and metabolism== | ==Cell structure and metabolism== |
Revision as of 00:50, 10 May 2012
A Microbial Biorealm page on the genus BottsE
Classification
Higher order taxa
Bacteria; Actinobacteria; Actinobacteria; Bifidobacteriales; Bifidobacteriaceae; Bifidobacterium [Others may be used. Use NCBI link to find]
Species
NCBI: Taxonomy |
Bifidobacterium longum
Description and significance
Tissier first discovered the genus Bifidobacterium in the feces of breast-fed infants in 1900, even though the name Bifidobacteria did not arise until the early 1960s (1). Bifidobacteria are Gram-positive, non-spore forming, rod-shaped bacteria. Specifically, Bifidobacterium longum are often found clumped together in irregular B or Y shaped branching patterns, although the morphology can vary depending on growth phase (figure 1) (5). Bifidobacteria average about 2.5 mm in diameter, they are non-motile, and anaerobic (except they may tolerate oxygen in the presence of CO2). In terms of metabolic tests, bifidobacteria are catalase negative, benzidine reaction negative, indole negative, and they do not reduce nitrates (3). They are also starch negative and lactose positive (1). They are typically found associated with hosts (primarily mammals), but they have also been found in insect and bird GITs, among other places (5). For humans, they play an extremely important role in forming a stable microbial colony in the GI tract, among other beneficial functions (8).
Currently, there are 25 known species of Bifidobacteria, including B. longum.
Genome structure
The circular genome of B. longum contains 2, 256, 656 base pairs, with 60% of them being G-C pairs. 86% of these genes are thought to be coding (1,730 coding regions), and 22% are specific to B. longum (unless they have yet to be identified in other species). The genome codes for 4 nearly identical rrn operons, 57 tRNAs that code for all 20 amino acids, and 16 intact insertion sequence elements (7). In terms of plasmids, they have been found in 70% of the sequenced B. longum strains, and 7 different types have been identified. Furthermore, some strains harbor defective lysogenic phages, which are dormant plasmids that still contain DNA (1).
The sequence of B. longum subspecies infantis shows a large inverted region (about 1.3 Mb) in the middle of the genome compared to both B. longum strains. This inversion could possibly be a recent evolutionary event (6).
Cell structure and metabolism
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Ecology
Habitat; symbiosis; contributions to the environment.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Current Research and or Application to Biotechnology
Enter summaries of the most recent research and/or application to biotechnology here--at least three required
References
Edited by student of Dr. Lynn M Bedard, DePauw University http://www.depauw.edu