Lipase-producing microorganisms from a Kenyan alkaline soda lake

Abstract

Lipolytic enzyme production of 150 isolated strains from samples of Lake Bogoria (Kenya) was examined. Among these, fifteen isolates were selected on the basis of their lipolytic activities and subjected to morphological and 16S rRNA gene sequencing analyses for their identification. All the microorganisms have been selected under culture conditions with pH ranges between 7-10 and temperatures of 37-55 degrees C. Most of them showed optimal growth at 37 degrees C and tolerated salinity up to 10% (w/v). Ten of the isolates were Gram-negative, nine of which were closely related to the Pseudomonas cluster and one to the Halomonas cluster sharing high similarity profile with Halomonas desiderata. The remaining Gram-positive isolates were closely related to the Bacillus cluster, and were grouped with Bacillus halodurans, Bacillus alcalophilus and Bacillus licheniformis. Four members of the Bacillus cluster and the Halomonas sp. produced lipolytic activity under alkaline conditions, while others did so at neutral pH values.