Methanosaeta thermophila

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Methanosaeta thermophila


● ~Classification~

            Organism Name:	Methanosaeta thermophila PT
                   Domain:	Archaea
                   Phylum:	Euryarchaeota
                    Class:	Methanomicrobia
                    Order:	Methanosarcinales
                   Family:	Methanosaetaceae
                    Genus: 	Methanosaeta
                  Species:     Methanothrix thermophila
     Genus Species Strain:     Methanosaeta thermophila PT
             Name History:	Synonyms: Methanothrix thermophila PT
                                         Methanothrix thermophila DSM 6194 
                               Equivalent names: Methanosaeta thermophila strain PT
                                                 Methanosaeta thermophila str. PT

●~Description and Significance~


            Methanosaeta thermophila are a diverse group of widely distributed anaerobic 
 archaea that inhabit anaerobic environments, such as the intestinal tracts of animals, freshwater   
and marine sediments, sewage, anaerobic biofilms, and anaerobic sediments. These archaea are  
methanogens, which means they are capable of producing methane from a limited number of substrates, 
including carbon dioxide, hydrogen, acetate, and methylamines. Methanosaeta thermophila are 
nonmotile, nonsporulating, and thermophilic, which means they thrive at temperatures of 50ºC or 
higher.
          This microbe was discovered by a molecular technique using fluorogenic PCR (polymerase
chain reaction, which amplifies DNA) to identify its methanotrophic characteristics and activity
in marine anoxic microbial communities. This was accomplished by identifying and quantifying the
mcrA genes. Following amplification, molecular analysis was performed by clone analysis of the 
16S rRNA and mcrA genes.  The mcrA genes (encoding the methyl coenzyme M reductase, specific to 
methanogenic archaea), are specific to the various phylogenetic groups of methanotropic Archaea.  
Methanosaeta thermophila was identified among the microbial communities in deep sediments and 
“methane seepages of Omine Ridge in the Nankai Trough accretionary prism,” (1).  
           The addition of Methanosaeta to the methanoarchaeal genome sequence compilation offered
an opportunity to gain significant insight into this intricate microbe and the unique use of 
comparative genomic approaches allows one to address the nature of these specific microbes and  
their biological influence and capability. Because these microbes are methanogens, they serve an 
important role as the producers of natural gas and have potential as creators of biofuels (fuels 
derived from a biomass).

●~Genome Structure~

           The Methanosaeta thermophila’s genome has been entirely sequenced.  These microbes   
possess circular chromosomes and do not contain plasmids. (The following genome sequence 
information, list, and map of the Methanosaeta thermophila chromosome was taken from eleventh 
source listed under the references section.)
        Genome Sequence: RS: NC_008553     
        Genome Sequence Length: 1879471 
        Statistics: Number of nucleotides: 1879471
                    Number of protein genes: 1696
                    Number of RNA genes: 51
         Genome Statistics                     Number	% of Total
             DNA, total number of bases         total    100.00%		
             DNA G+C number of bases		            0.00% 
             DNA scaffolds	                      0	  100.00%
             Genes total number	              0	  100.00%
             Protein coding genes	              0	    0.00%
             RNA genes	                              0	    0.00%
             rRNA genes	                      0	    0.00%
             5S rRNA	                              0	    0.00%
             16S rRNA	                              0	    0.00%
             18S rRNA	                              0	    0.00%
             23S rRNA	                              0	    0.00%
             28S rRNA	                              0	    0.00%
             tRNA genes                              0	    0.00%
             Other RNA genes	                      0	    0.00%
             Genes with function prediction          0	    0.00%
             Genes without function prediction       0	    0.00%

Genes w/o function with similarity 0 0.00%

             Genes w/o function w/o similarity       0	    0.00%
             Pseudo Genes	                      0	    0.00%
             Genes assigned to enzymes               0	    0.00%
             Genes connected to KEGG pathways	      0	    0.00%
             Genes not connected to KEGG pathway     0	    0.00%
             Genes in ortholog clusters	      0	    0.00%
             Genes in paralog clusters	              0	    0.00%
             Genes in COGs	                      0	    0.00%
             Genes in Pfam	                      0	    0.00%
             Genes in TIGRfam	                      0	    0.00%
             Genes in InterPro	                      0	    0.00%
             Genes with IMG Terms	              0	    0.00%
             Genes in IMG Pathways	              0	    0.00%
             Obsolete Genes	                      0	    0.00%
             Revised Genes	                      0	    0.00%
             Pfam clusters		              0     0.00%
             Paralogous groups		              0   100.00%
             Orthologous groups		      0     0.00%

●~Cell Structure and Metabolism~

Methanosaeta thermophila is circular (coccus), with one inner membrane and one cell wall. This microbe does not interact with other organisms, grows extremely slow, does not contain plasmids, does not possess flagella, but they do however produce gas vacuoles to help them move in aquatic environments. Gas vacuoles are cavities within the cytoplasm, which contain a gas similar to that of their surrounding atmosphere. These vacuoles serve as floatation devices because they decrease in size when subjected to increased hydrostatic pressure. So although they are nonmotile, their gas vacuoles allow some degree of flexibility in regards to how much movement they have in aquatic environments. Methanosaeta thermophila obtain their energy as a “thermophilic obligately-aceticlastic methane-producing archaeon,” which means that they produce methane from acetate, (4). Although approximately two-thirds of all methane is derived from the methyl group of acetate, Methanosaeta are able to utilize acetate as a substrate for methanogenesis. Methanosarcina is the only other genus of methanoarchaea that are capable of utilizing acetate as a substrate, as well as using H2/CO2, dimethylsulfide, and and methanethiol compounds as substrates. Unlike the faster-growing Methanosarcina, which prefers methylated compounds to acetate, Methanosaeta is a slow-growing specialist that utilizes acetate only.