C. Etchebehere et al., COPROTHERMOBACTER-PLATENSIS SP. NOV., A NEW ANAEROBIC PROTEOLYTIC THERMOPHILIC BACTERIUM ISOLATED FROM AN ANAEROBIC MESOPHILIC SLUDGE, International journal of systematic bacteriology, 48, 1998, pp. 1297-1304
A new anaerobic, proteolytic, moderately thermophilic bacterium, strai
n 3R(T), was isolated from a methanogenic mesophilic reactor treating
protein-rich wastewater. The cells were Gram-negative, non-spore-formi
ng, non-motile rods. The DNA base composition was 43 mol% G+C. The opt
imum ph and temperature for growth were 7.0 and 55 degrees C respectiv
ely. The bacterium fermented gelatin, casein, bovine albumin, peptone
and yeast extract. Glucose, fructose, sucrose, maltose and starch were
poorly fermented. The major fermentation products from glucose were a
cetate, CO2 and H-2 and, from gelatin, propionate was also detected. G
rowth on glucose was stimulated by thiosulfate, which was reduced to s
ulfide. Sulfate and nitrate were not reduced. 16S rRNA gene analysis r
evealed that the isolated bacterial strain was phylogenetically relate
d to Coprothermobacter proteolyticus (96.3 % sequence similarity), the
only known species within the genus. DNA-DNA hybridization analysis d
emonstrated a very low level of homology, indicating that the isolated
strain and C. proteolyticus were not related at species level. Theref
ore, it is proposed to classify the described strain in the genus Copr
othermobacter as a new species, Coprothermobacter platensis. The type
strain of C. platensis is strain 3R(T) (= DSM 11748(T)).