Methanothermobacter
From MicrobeWiki, the student-edited microbiology resource
A Microbial Biorealm page on the genus Methanothermobacter
Methanogens overview
Contents |
Classification
Higher order taxa:
Archaea; Euryarchaeota; Methanobacteria; Methanobacteriales; Methanobacteriaceae
Species:
Methanothermobacter thermoautotrophicus str. Delta H (Methanobacterium thermoautotrophicus), M. wolfeii (Methanobacterium wolfeii)
Description and Significance
Isolated from a municipal waste-treatment facility, Methanothermobacter thermoautotrophicus is widely studied as a representative of the methanogens that inhabit all biodegrading facilities.
Genome Structure
The genome was found to be circular with 1,751,377 bp. Some unique features of the genome include the presence of two Cdc6 homologs, an archaeal B-type DNA polymerase with a novel subunit structure, and two introns in the same tRNAPro(CCC) gene. While this is a methanogen, compared to Methanocaldococcus jannaschii their genomes are pretty different. The pathway and regulation of methane appear conserved, but other than that 20% of the genes in M. thermoautotrophicus are not present in M. jannaschii, and 15% of M.j. genes are not present in M.t. Less than 1% of their proteins have sequences more than 70% identical.
Cell Structure and Metabolism
M. thermoautotrophicus is an anaerobic lithoautotrophic thermophilic that requires only CO2, H2, and salts for growth. Its rod shape is maintained by a rigid layer of pseudomurein, which is similar to the murein layer found on Bacteria. M. thermoautotrophicus has a cell width of 0.3-0.6 microns and a cell length of 2-7 microns. M. wolfeii has a cell width and length of 0.4um and 2.4-2.7um respectively. They are both Gram-positive as well.
Ecology
M. thermoautotrophicus was first isolated in 1971 from sewage sludge in Urbana, Il. This archaeon grows at temperatures ranging from 40 to 70oC and optimally at 65oC.
References
Smith et al. 1997. Complete Genome Sequence of Methanobacterium thermoautotrophicum Delta H: Functional Analysis and Comparative Genomics. Journal of Bacteriology vol. 179 no. 22: 7135-7155
The Ohio State University Dept. of Microbiology. 1997. M. thermoautotrophicum.
