Rhizobium etli: Difference between revisions
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==Genome structure== | ==Genome structure== | ||
Rhizobium Etli has a complete genome sequence of 6,530,228 base pairs. It contains 4,381,608 circular chromosomes averaging 61.27% GC content. Six plasmids: p42a, p42b, p42c, p42d, p42e, and p42f, contain the complete metabolic pathways. The p42a and p42d plasmids contain genes that are abnormal, which indicate evidence of being acquired during divergence of the bacteria. The other four plasmids are consistent with other genes and chromosomes, indicating coevolution. | |||
In addition, replicons are the most abundant when comparing to other known nitrogen-fixing bacteria. Rep ABC replicator present in the plasmid allows stability with distinct initiators and origins of replication. An advantage to the separation of genomes is faster duplication to replicate its genome. | |||
Lateral gene transfer, 23 sigma factors, isozymes, and genomic plasticity are necessary for its symbiotic lifestyle in the soil. | |||
==Cell structure and metabolism== | ==Cell structure and metabolism== | ||
Revision as of 06:28, 27 August 2007
A Microbial Biorealm page on the genus Rhizobium etli
Classification
Higher order taxa
Bacteria (Domain); Proteobacteria (Phylum); Alphaproteobacteria (Class); Rhizobiales (Order); Rhizobiaceae (family)
Species
Rhizobium Etli
Description and significance
Rhizobium Etli is one of the many soil-living bacteria able to live in conditions of nitrogen limitation due to its distinctive ability to settle onto root nodules of legumes. Like other rhizobia, it is characterized as aerobic,gram negative and able to form symbiotic relationship with legumes. (1, 2) In specific, rhizobium etli is the predominant bacteria found legumes such as the common bean, P. Vulgaris. (3)
Rhizobium Etli is found world wide and discovered as early as 16th century. Due to its early existence, attempts to identify origin of the species was performed by identifying its molecular marker. This was performed by searching a diversity within different rhizobium etli species from P. Vulgaris. Isolation of the rhizobia strain from the nodule of the root of the plant was removed, sterilized with ethanol and hydrogen peroxides, and grown on YEM-Congo red agar medium. Isolation and identification was done by 16S rRNA-encoding DNA-RFLP analysis. The analysis showed most to be from species rhizobium etli. The nodC gene was identified and isolated to be used as a molecular marker. Results from the experiment showed rhizobium etli is not only found in the America’s but also identified in parts of Africa, Asia, and Europe. (3)
Rhizobium Etli is important enough to have its genome sequence because of its unique ability to form symbiotic relationship with legumes. The detail in which it performs this will be in the cell structure and metabolism section. To give a general idea of its importance, the host benefits by being provided nitrogen in the form of ammonia from the bacteria, while the bacteria is provided carbon and nutrients from the host. (2)
In agriculture, crop rotation and soil fumigation is performed each year to prevent diseases. Futher knowledge of the bacteria would allow possible genetic engineering onto the bacteria to possibly work as an antibiotic. (4)
Genome structure
Rhizobium Etli has a complete genome sequence of 6,530,228 base pairs. It contains 4,381,608 circular chromosomes averaging 61.27% GC content. Six plasmids: p42a, p42b, p42c, p42d, p42e, and p42f, contain the complete metabolic pathways. The p42a and p42d plasmids contain genes that are abnormal, which indicate evidence of being acquired during divergence of the bacteria. The other four plasmids are consistent with other genes and chromosomes, indicating coevolution. In addition, replicons are the most abundant when comparing to other known nitrogen-fixing bacteria. Rep ABC replicator present in the plasmid allows stability with distinct initiators and origins of replication. An advantage to the separation of genomes is faster duplication to replicate its genome. Lateral gene transfer, 23 sigma factors, isozymes, and genomic plasticity are necessary for its symbiotic lifestyle in the soil.
Cell structure and metabolism
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
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
