Degradative Potential Of Bacteria Isolated From Crude Oil Contaminated Soil

Petroleum and its products continue to serve as a principle source of energy for industries and daily life. However, their release into the environment is a worldwide concern since some products are acutely toxic or possess mutagenic, teratogenic and carcinogenic properties. Several oil disposal methods have been applied over time with remediation emerging as the most promising technology. It takes advantage of the versatility of soil microbes to degrade hydrocarbon contaminants. Unlike conventional disposal methods, bioremediation ids an environmentally friendly and cost effective method that stimulate natural processes for complete degradation of hydrocarbons into innocuous compounds. This study focused on isolation, morphological and biochemical characterization of bacteria possessing hydrocarbon degrading properties. The study also aimed at optimizing appropriate culture conditions for the isolates. Isolation of hydrocarbon degrading bacteria from soils polluted with crude oil in Elebel, Emeyal I, Emeyal II in Ogbia, Bayelsa State was carried out using mineral salt medium supplemented with 1% crude oil, and the isolates were screened on their ability to use carbon as their sole source of carbon or alternative pathway. Characterization of the isolates was carried out by performing Grams iodine test, catalase, oxidase, indole, citrate, motility, coagulase tests. The degrading potential of the isolates were obtained by subculturing them in mineral salt medium for two weeks at room temperature, organisms that could utilize all crude oil made available to them were considered strong degraders while those that could not utilize all the crude oil made available to them were considered weak degraders. Among 40 microbes isolated, 30 were considered strong degraders while 10 were considered weak degraders and these isolates included Pseudomonas spp, Enterobacter spp, Escherichia coli, Arthrobacter spp, Bacillus spp, Acinetobacter spp, Staphylococcus aureus, coagulase negative Staphylococcus spp, Klebsiella spp, Micrococcus spp, Vibrio spp. The characterized isolates may constitute potential candidates for biotechnological application in environmental cleanup of petroleum contaminants.