Methanobrevibacter smithii

Tzeng et al. [328] first reported the use of F420 as an electron acceptor for formate oxidation in extracts of Methanobrevibacter smithii, but proof of the role of F420 in FDH catalysis was obtained by purification of this enzyme from Methanococcus va n/e/i( [48,49,329] mA Methanobacteriumydr/w/dc m [327,330-332]. Most enzymatic detail of the methanogen FDH comes from study of these two organisms. A review on FDH has recently been published by Ferry [253],... 

Ornithine is found in addition to lysine (e.g., Methanobrevibacter smithii strain PS and Methanopyrus kandleri). In Methanobrevibacter smithii, ornithine was found to be attached to the a-carboxylic group of a glutamic acid residue (Fig. 3). 

The amino-acid sequence deduced for the M. thermoautotrophicum SOD most closely resembles bacterial, archaeal and eucaryal Mn-SODs, however atomic absorption spectroscopy has established that this is a Fe-SOD [305]. In contrast to other Fe-SODs, including the Fe-SOD from Methanobrevibacter smithii [302], this enzyme is resistant to azide and hydrogen peroxide, features it has in common with Mn-SODs [305]. Amino-acid residues identified as metal ligands or active sites are, however, conserved in both Mn-SODs and Fe-SODs, implying that all these enzymes have a common ancestry and similar enzyme mechanisms [63]. 

Million M, Maraninchi M, Henry M, et al. Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevibacter smithii. Int J Obesity. 2012 36(6) 817—825. 

Million M, Angelakis E, Maraninchi M, et al. Correlation between body mass index and gut concentrations of Lactobacillus reuteri. Bifidobacterium animalis, Methanobrevibacter smithii and Escherichia coli. Int J Obesity. 2013 37(11) 1460—1466. 

Several species have been isolated, studied in pure culture, and taxonomi-cally identified and classified. Some of the notable species are Methanobacterium formicicum, M. bryantii, M. thermoautotrophicum Methanobrevibacter ruminant-ium, M. arboriphilus, M. smithii Methanococcus vannielii, M. voltae Methanomicrobium mobile Methanogenium cariaci, M. marisnigri Methanospirillum hunga-... 

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