Sinorhizobium meliloti: Difference between revisions

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==Description and significance==
==Description and significance==


Sinorhizobium meliloti is a gram-negative bacterium.  As are other Rhizobia, S. meliloti can be found as a normal, free-living microorganisms in the soil.  However, it is for their nitrogen-fixing symbiotic relationships with legumes that S. meliloti are studied.  S. meliloti cells detect substances particularly made up of amino and organic acids, released by the roots of plants.  The cells are drawn toward root hairs that emerge from the roots and induce the root hair tips to curl up.  There is a cytoplasmic bridge formed by the microtubules and the cytoplasm of the root cells.  This bridge guides infection threads extending from the roots to the cortex of the bacterial cells.  Finally, the S. meliloti cells enter the cytoplasm of the root cells through endocytosis.  S. meliloti transform atmospheric nitrogen into a form that may be utilized by the host in which they reside.  Also, the S. meliloti is significant in that it leaves behind excess nitrogen in the soil which may potentially reduce the need for fertilizers.      
Sinorhizobium meliloti is a gram-negative bacterium.  As are other Rhizobia, S. meliloti can be found as a normal, free-living microorganisms in the soil.  However, it is for their nitrogen-fixing symbiotic relationships with legumes that S. meliloti are studied.  S. meliloti cells detect substances particularly made up of amino and organic acids, released by the roots of plants.  The cells are drawn toward root hairs that emerge from the roots and induce the root hair tips to curl up.  There is a cytoplasmic bridge formed by the microtubules and the cytoplasm of the root cells.  This bridge guides infection threads extending from the roots to the cortex of the bacterial cells.  Finally, the S. meliloti cells enter the cytoplasm of the root cells through endocytosis.  S. meliloti transform atmospheric nitrogen into a form that may be utilized by the host in which they reside.  Also, the S. meliloti is significant in that it leaves behind excess nitrogen in the soil which may potentially reduce the need for fertilizers. The S. meliloti genome was isolated and sequenced from nodules and soil primarily from host plants such as the Medicago (alfalfa and perennial and annual medics), Melilotus (sweet clover), and Trigonella (fenugreek) species. The detailed study of S. meliloti and other Rhizobia will further inform microbiologists about how these bacteria colonize root surfaces of their host and what mechanisms make-up the complex rhizobium-legume symbiotic relationship.
 
 
Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced.  Describe how and where it was isolated.
Include a picture or two (with sources) if you can find them.


==Genome structure==
==Genome structure==

Revision as of 05:16, 28 August 2007

A Microbial Biorealm page on the genus Sinorhizobium meliloti

Classification

Higher order taxa

Bacteria; Proteobacteria; Alphaproteobacteria; Rhizobiales; Rhizobiazeae; Sinorhizobium


[Others may be used. Use NCBI link to find]

Species

NCBI: Taxonomy

Sinorhizobium meliloti;

Description and significance

Sinorhizobium meliloti is a gram-negative bacterium. As are other Rhizobia, S. meliloti can be found as a normal, free-living microorganisms in the soil. However, it is for their nitrogen-fixing symbiotic relationships with legumes that S. meliloti are studied. S. meliloti cells detect substances particularly made up of amino and organic acids, released by the roots of plants. The cells are drawn toward root hairs that emerge from the roots and induce the root hair tips to curl up. There is a cytoplasmic bridge formed by the microtubules and the cytoplasm of the root cells. This bridge guides infection threads extending from the roots to the cortex of the bacterial cells. Finally, the S. meliloti cells enter the cytoplasm of the root cells through endocytosis. S. meliloti transform atmospheric nitrogen into a form that may be utilized by the host in which they reside. Also, the S. meliloti is significant in that it leaves behind excess nitrogen in the soil which may potentially reduce the need for fertilizers. The S. meliloti genome was isolated and sequenced from nodules and soil primarily from host plants such as the Medicago (alfalfa and perennial and annual medics), Melilotus (sweet clover), and Trigonella (fenugreek) species. The detailed study of S. meliloti and other Rhizobia will further inform microbiologists about how these bacteria colonize root surfaces of their host and what mechanisms make-up the complex rhizobium-legume symbiotic relationship.

Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?

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

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Rachel Larsen