SELENOMONAS LIPOLYTICA SP. NOV., AN OBLIGATELY ANAEROBIC BACTERIUM POSSESSING LIPOLYTIC-ACTIVITY

A novel, obligately anaerobic bacterium capable of hydrolysing lipids was isolated from a tropical anaerobic lagoon receiving waste water fr om an edible oil mill. The isolate had many characteristics similar to those of members of the genus Selenomonas. The isolate showed lipolyt ic activity on tributyrin, triolein and groundnut oil in qualitative p late clearance assays, which has not been reported for the type strain of the genus Selenomonas. It did not require n-valerate supplementati on for growth on glucose. Acetate and propionate were the only volatil e fatty acids produced from glucose fermentation with propionate as th e major end product. The isolate could grow optimal;ly at ph 6.8 and a t a temperature of 40 degrees C. It could tolerate NaCl concentrations of up to 40 g l(-1). The G+C content of the DNA was 40 mol% as determ ined by thermal denaturation analysis. Comparison of partial 16S rRNA gene sequences revealed that the isolate was most closely related to g enus Selenomonas with 91% sequence similarity (250 bp compared) to Sel enomonas ruminantium strain GA 192. On the basis of the results obtain ed in the present investigation, ii: is suggested that a new species o f Selenomonas should be created for this novel isolate and the name Se lenomonas lipolytica is proposed for this new species. The type strain is strain CF1B(T) (= MCMB 505(T)).