Abstract
Soil sample from commercial kitchen was examined for the presence of lipolytic bacteria. Lipolytic activity was screened by using Rhodamine B and tween 80 as lipid substrates. Twenty strains were isolated from the sample, of which twelve strains (SN-1, SN-2, SN-3, SN-7, SN-9, SN-10, SN-12, SN-14, SN-15, SN-17, SN-19, & SN-20) showed lipolytic potential. SN-12 and SN-20 showed low lipolytic potential on two different screening media. Submerged fermentation was carried out to collect cell free filtrate as source of crude lipase and to quantitatively monitor its lipolytic activity. The strain SN-3 showed highest lipase activity i.e. 14.91 + 0.09 U/mL and therefore it was selected as a potential lipase producing bacteria to carry out further studies. The isolate SN-3 showed large, wrinkled and opaque colonies. Microscopic observation revealed the isolate as gram negative, rod shaped, non-spore former, and nonpigmented bacteria. According to biochemical analysis, the isolated strain is a motile, hemolytic bacterium. It is able to hydrolyze starch and fix nitrogen. The isolate is halotolerant and sustain up to 7% of NaCl and can grow in pH 4.5. In the light of these findings, the strain SN-3 has been characterized as Pseudomonas stutzeri. This is a potential lipolytic bacterial strain and can be further identified through molecular technologies.
