POTENCY OF BACTERIA ISOLATED FROM SOILS OF SELECTED OIL POLLUTED MECHANIC WORKSHOPS IN OKITIPUPA LGA TO DEGRADE CRUDE OIL

Abstract

The main purpose of this study was to isolate bacteria with potency for biodegradation of crude oil, a chronic environmental pollutant in the Niger- Delta region of Nigeria. Using cultural and biochemical characterization, six bacteria genera namely Pseudomonas, Bacillus, Sphingomonas, Micrococcus, Staphylococcus, and Corynebacterium were isolated from the oil polluted soils of mechanic workshops. Degradation potentials of the isolates were tested in Mineral Salt Medium (MSM) supplemented with varying concentrations of crude oil (1%, 2%, 3%, 5% and 7%) as the only carbon source in an orbital shaker over a 7-day period. Using fluorescence- based assay, fluorescence intensity (FI) which correlates with the amount of crude oil present was measured through spectrophotometer revealing Optical densities of 1.872, 1.790,1.721, 1.538,1.420 and 1.386 for Staphylococcus, Pseudomonas, Corynebacterium, Micrococcus, Sphingomonas and Bacillus respectively. Order of degradation was Bacillus > Sphingomonas > Micrococcus > Corynebacterium > Pseudomonas > Staphylococcus. Higher degradation recorded lower fluorescence due to reduced oil content. Best degradation for Bacillus, Sphingomonas, Micrococcus and Corynebacterium occurred at 3% crude oil concentration while Pseudomonas and Staphylococcus had the best degradation at 1% concentration. It was then concluded that the isolates could be developed to remediate crude oil pollutants rampant across the Delta Niger region of Nigeria.