Thermophilic bacterial isolates producing lipase

Abstract

A number of lipase-producing thermophilic bacteria were isolated from natural habitats. One isolate, obtained from a coal tip sample, was examined in some detail: it was a highly thermophilic Bacillus sp. (optimum growth temperature approx. 65°C) and at 55°C it produced the maximum level of lipase (about 4 U/ml) in a medium containing Tween-80 (polyoxyethylene sorbitan monooleate) as the principal carbon source when growth had virtually ceased. Lipase synthesis thus appears to be inducible, and since a very low level of lipase was observed when the isolate was grown in a medium containing a carbon source like glucose as well as Tween-80, lipase synthesis is apparently also subject to catabolite repression.