Shewanella amazonensis: Difference between revisions

From MicrobeWiki, the student-edited microbiology resource
Line 19: Line 19:


==Genome structure==
==Genome structure==
Conventional phenotypic and chemotaxonomic analyses identified strain SB2BT as ''S. putrefaciens.''  However, PCR probes designed to recognize ''S. putrefaciens'' based on gyrB (encoding the B subunit of DNA gyrase, topoisomerase II) failed to generate a specific amplicon for SB2BT, indicating that this strain may represent a new species.  To elucidate the phylogenetic status of SB2BT, its 16S rDNA and gyrB gene sequences were analysed. Both sequences differ from all known Shewanellae, suggesting that the organism does indeed deserve the status of new species.  The G+C content of the DNA is 51.7 mol%.   The type strain, SB2BT, has been deposited with the American Type Culture Collection as ATCC 700329T.
Analysis of the 16S rDNA sequence revealed a clear affiliation between strain SB2BT and members of the gamma subclass of the class Proteobacteria. High similarity values were found with certain members of the genus Shewanella, especially with Shewanella putrefaciens, and this was supported by cellular fatty acid profiles and phenotypic characterization. DNA–DNA hybridization
between strain SB2BT and its phylogenetically closest relatives revealed low similarity values (24<6–42<7%) which indicated species status for strain SB2BT.  That SB2BT represents a distinct bacterial species within the genus Shewanella is also supported by gyrB sequence analysis. Considering the source of the isolate, the name Shewanella amazonensis sp. nov. is proposed and strain SB2BT (ATCC 700329T) is designated as the type strain.


==Cell structure and metabolism==
==Cell structure and metabolism==

Revision as of 07:53, 6 December 2007

A Microbial Biorealm page on the genus Shewanella amazonensis

Classification

Higher order taxa

Bacteria (Domain); Proteobacteria (Phylum); Gammaproteobacteria (Class); Alteromonadales (Order); Shewanellaceae (Family); Shewanella (Genus)

Species

NCBI: Taxonomy

Shewanella amazonensis

Description and significance

Shewanella amazonensis (strain ATC BAA-1098/SB2B) is a Gram-negative, facultatively anaerobic, motile, polarly flagellated, rod-shaped eubacterium. It is exceptionally active in the anaerobic reduction of iron, manganese and sulfur compounds. It was isolated from shelf coastal muds, in intertidal sediments in the Amazon River delta, off the Amapa coast of Brazil.

Genome structure

Analysis of the 16S rDNA sequence revealed a clear affiliation between strain SB2BT and members of the gamma subclass of the class Proteobacteria. High similarity values were found with certain members of the genus Shewanella, especially with Shewanella putrefaciens, and this was supported by cellular fatty acid profiles and phenotypic characterization. DNA–DNA hybridization between strain SB2BT and its phylogenetically closest relatives revealed low similarity values (24<6–42<7%) which indicated species status for strain SB2BT. That SB2BT represents a distinct bacterial species within the genus Shewanella is also supported by gyrB sequence analysis. Considering the source of the isolate, the name Shewanella amazonensis sp. nov. is proposed and strain SB2BT (ATCC 700329T) is designated as the type strain.

Cell structure and metabolism

Interesting features of cell structure; how it gains energy; what important molecules it produces.


Ecology

Habitat; symbiosis; contributions to environment.

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

References

Venkateswaran, K., M. E. Dollhopf, R. Aller, E. Stackebrandt, and K. H. Nealson. 1998. Shewanella amazonensis sp. nov., a novel metal-reducing facultative anaerobe from Amazonian shelf muds. International Journal of Systematic Bacteriology 48: 965-972.