A new species of thermophilic marine methanogenic bacteria is described. Cells of this species occurred as irregular cocci, singly or in pairs, and did not possess flagella. Colonies were translucent, beige in color, and circular with entire edges. Either formate or hydrogen and carbon dioxide could serve as a substrate for growth and methane formation, whereas ethanol, methanol, acetate, propionate, and pyruvate could not. The temperature for optimum growth was 55°C, with minimal growth below 37°C and an upper temperature limit of 65°C. The pH for optimum growth was 7.0. Sodium chloride was required for growth; the concentration for optimum growth was 0.20 M. The minimum generation time was 2.5 h. The deoxyribonucleic acid base composition was 59 mol% guanine plus cytosine. The name Methanogenium thermophilicum is proposed for this organism. The type strain is CR-1 (= ATCC 33837 = DSM 2373).
BalchW. E.,
WolfeR. S.1976; New approach to the cultivation of methanogenic bacteria: 2-mercaptoethane-sulfonic acid (HS-CoM)-dependent growth of Methanobacterium ruminatium in a pressurized atmosphere. Appl. Environ. Microbiol 32:781–791
BryantM. P.,
RobinsonI. M.1961; An improved non-selective culture medium for ruminal bacteria and its use in determining diurnal variation in number of bacteria in the rumen. J. Dairy Sci 44:1446–1456
CheesemanP.,
Toms-WoodA.,
WolfeR. S.1972; Isolation and properties of a fluorescent compound, factor420, from Methanobacterium strain M.o.H. J. Bacteriol 112:527–531
PrestonJ. R.,
BooneD. R.1973; Analytical determination of the buoyant density of DNA in acrylamide gels after preparative CsCl gradient centrifugation. FEBS Lett 37:321–324
RomesserJ. A.,
WolfeR. S.,
MayerF.,
SpiessE.,
Walther-MauruschatA.1979; Methanogenium, a new genus of marine methanogenic bacteria, and characterization of Methanogenium cariaci sp. nov. and Methanogenium marisnegri sp. nov. Arch. Microbiol 121:147–153
SchildkrautC. L.,
MarmurJ.,
DotyP.1962; Determination of the base composition of deoxyribonucleic acid from its buoyant density in CsCl. J. Mol. Biol 4:430–443