M ethanoplanus

Abstract

Me.tha.no.pla'nus. N.L. neut. n. methanum methane; N.L. pref. methano‐ pertaining to methane; N.L. masc. adj. planus flat; N.L. masc. n. Methanoplanus the methane (−producing) plate. Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanomicrobiaceae / Methanoplanus Cells are angular, crystal‐like plates, or disc shaped. They are 1–3.5‐µm long, 1–2‐µm wide, and only 0.07–0.3‐µm thick. They occur singly or in pairs and are sometimes branched, without septa. Stain Gram‐negative. Flagella or pilus‐like structures are found. Strictly anaerobic. Chemolithotrophic growth on H 2 and CO 2 or formate. These substrates serve as an energy source for growth and methane formation. No growth on methanol or methylamines. During growth on molecular hydrogen in the presence of S 0 , H 2 S is formed in addition to methane. The organisms are mesophilic, with optimum growth temperatures between 32 and 40°C at neutral pH. On the basis of the 16S rRNA sequence data, Methanoplanus belongs to the family Methanomicrobiaceae . DNA G + C content (mol%) : 39–47.5. Type species : Methanoplanus limicola Wildgruber, Thomm and Stetter 1984, 270 VP (Effective publication: Wildgruber, Thomm, König, Ober, Richiuto and Stetter 1982, 36).