THERMOSYNTROPHA LIPOLYTICA GEN-NOV, SP-NOV, A LIPOLYTIC, ANAEROBIC, ALKALITOLERANT, THERMOPHILIC BACTERIUM UTILIZING SHORT-CHAIN AND LONG-CHAIN FATTY-ACIDS IN SYNTROPHIC COCULTURE WITH A METHANOGENIC ARCHAEUM

Three strains of an anaerobic thermophilic organoheterotrophic lipolyt ic alkalitolerant bacterium, Thermosyntropha lipolytica gen, nov., sp. nov, (type strain JW/VS-265(T); DSM 11003), were isolated from alkali ne hot springs of Lake Bogoria (Kenya), The cells were nonmotile, non- spore forming, straight or slightly curved rods. At 60 degrees C the p H range for growth determined at 25 degrees C [pH(25 degrees C)] was 7 .15 to 9.5, with an optimum between 8.1 and 8.9 (pH(60 degrees C) Of 7 .6 and 8.1). At a pH(25 degrees C) of 8.5 the temperature range for gr owth was from 52 to 70 degrees C, with an optimum between 60 and 66 de grees C, The shortest doubling time was around 1 h. In pure culture th e bacterium grew in a mineral base medium supplemented with yeast extr act, tryptone, Casamino Acids, betaine, and crotonate as carbon source s, producing acetate as a major product and constitutively a lipase. D uring growth in the presence of olive oil, free long-chain fatty acids were accumulated in the medium but the pure culture could not utilize olive oil, triacylglycerols, short- and long-chain fatty acids, and g lycerol for growth, In syntrophic coculture (Methanobacterium strain J W/VS-M29) the lipolytic bacteria grew on triacylglycerols and linear s aturated and unsaturated fatty acids with 4 to 18 carbon atoms, but gl ycerol was not utilized, Fatty acids with even numbers of carbon atoms were degraded to acetate and methane, while from odd-numbered fatty a cids 1 mol of propionate per mol of fatty acid was additionally formed . 16S rDNA sequence analysis identified Syntrophospora and Syntrophomo nas spp, as closest phylogenetic neighbors.