Anaerophaga thermohalophila gen. nov., sp nov., a moderately thermohalophilic, strictly anaerobic fermentative bacterium

The strictly anaerobic Gram-negative bacterium strain Fru22(T) grows at 50 degreesC in media containing up to 75 g NaCl l(-1). Hexoses and pentoses are fermented to equal molar amounts of acetate, propionate and succinate, and no CO2 is formed. An orange-red pigment similar to flexirubin is produced during stationary phase upon exposure to light for several days. Cells also produce a surface-active extracellular compound which lowers the surface tension of the medium. This tenside is heat-tolerant up to 70 degreesC and is destroyed by treatment with proteinase K or trypsin, but not by lipase. Comparative 165 rDNA sequence analysis confirmed a phylogenetic affiliation of strain Fru22(T) to the phylum Bacteroides (Cytophaga/Flavobacterium/Bacteroides), moderately related to the genus Marinilabilia. Therefore, on the basis of phylogenetic, phenotypic and physiological evidence, a new genus, Anaerophaga, is proposed to harbour strain Fru22(T) (DSM 12881(T), OCM 798(T)) which is described as the type strain of a new species, Anaerophaga thermohalophila gen. nov., sp. nov.