Methanolobus zinderi sp nov., a methylotrophic methanogen isolated from a deep subsurface coal seam

A methanogenic organism from the domain Archaea (SD1(T)) was isolated from saline water released from a coal seam located 926 m below the surface via a methane-producing well near Monroe, Louisiana, USA. Growth and methanogenesis were supported with methanol, monomethylamine, dimethylamine or trimethylamine, but not with dimethylsulfide, formate, acetate or H-2/CO2. Cells grew in high-salt minimal medium but growth was stimulated with yeast extract or tryptone. Cells were single, non-motile, irregular coccoids 0.5-1.0 mu m in diameter and the cell wall contained protein. Conditions for the maximum rate of growth were 40-50 degrees C, 0.2-0.6 M NaCl, 100- >= 200 mM MgCl2, and pH 7.0-8.0. The G + C content of the genomic DNA was 42 +/- 1 mol%. A comparison of 16S rRNA gene sequences indicated that strain SD1(T) was most closely related to Methanolobus oregonensis DSM 5435(T) with 96% gene sequence similarity. It is proposed that strain SD1(T) represents a novel species, Methanolobus zinderi sp. nov. The type strain is SD1(T) (=ATCC BAA-1601(T)=DSM 21339(T)).