Microorganisms Associated with Vegetable Oil Polluted Soil

Abstract

Vegetable oil Spills are becoming frequent and are potentially more challenging than petroleum hydrocarbon spills. Microbial lipases occupy a place of prominence among biocatalysts are often used for remediation of vegetable oil-polluted sites. This work was carried out to isolate microorganisms from oil-polluted sites and screen them for their lipolytic activity. Microorganisms were isolated from eight experimental soil samples contaminated with different types of vegetable oil, soil from an oil mill in Ibadan, and normal uncontaminated soil as a control. The isolates were characterized, identified and those common to at least one of the experimental sites and oil mill sites were screened for their lipolytic activity. Data obtained were analysed using Duncan Multiple Range Test. Seventy three microorganisms were isolated from the polluted soil and identified as species of Bacillus (16), Pseudomonas (12), Flavobacterium (6), Alcaligenes (2), Proteus (3), Micrococcus (1), Aspergillus (9), Penicillium (6), Saccharomyces (4), Geotrichum (1), Kluveromyces (1). Bacillus subtilis , Bacillus licheniformic , Pseudomonas cepacia , Pseudomonas fluorescens , Flavobacterium sp., Alcaligenes sp. and Candida parapsilosis which were common to at least one of the experimental site and oil mill site were preliminarily screened for lipolytic activity and all nine confirmed by presence of halos around the colonies. These screened organisms have potential for the degradation of fatty waste. They could therefore be employed in environmental clean-up of vegetable oil spill site.