ASSESSMENT OF MICROBIAL DEGRADATION OF BONNY LIGHT CRUDE OIL BY SOIL ISOLATES

Abstract

The role of microbial degradation of Bonny Light Crude Oil (BLCO) was assessed by laboratory determinations of counts of hydrocarbon utilizing bacteria, optical density and measurement of microbial hydrocarbon biodegradation potentials by gravimetric analysis of samples incubated for a two weeks period under room temperature. The bacteria isolated were members of the genera Pseudomonas, Alcaligenes, Corynebacteria, Bacillus and Arthrobacter. All the isolates caused the degradation of Bonny Light Crude Oil. (BLCO). Counts of hydrocarbon – utilizing population increased from 104 /ml to 1015/ml with concomitant increase in optical density. Bacillus sp showed the highest degradation with a percent degradation of 34.2%. Increase in counts of hydrocarbon utilizers and optical density in some cases did not reflect corresponding increase in rates of biodegradation. It therefore becomes necessary to utilize total viable count (TVC), optical density (O.D) and residual oil determinations in assessing the role of microbial degradation.