Hydrocarbon biodegradation by Proteus and Serratia strains isolated from oil-polluted water in Bonny Community, Niger Delta, Nigeria

Abstract

Two indigenous hydrocarbon utilizing bacteria strains, designated as TKZ and QGR were isolated in oil rich Niger Delta of Nigeria. Determination of the nucleotide sequence of the gene encoding 16S rRNA allowed TKZ and QGR to be identified as Proteus vulgaris and Serratia marcescens. Hydrocarbon degradation potential of the strains was confirmed on hydrocarbon mineral salts medium (1 %, v/v) at 37 °C. Assessment of oil degradation capability of the isolates was monitored using gas chromatographic analysis (GC). The ability of the strains to utilize benzene, diesel, kerosene, and naphthalene was also studied. The results show maximal increase in optical densities at 540 nm and total viable counts was proportional with decrease in pH of the culture media. Percentage degradation in the culture medium showed that the two isolates exhibited biodegradation efficiency above 90 % for kerosene. The two bacterial strains also possess a plasmid of about 9.1 kb size which is suspected to influence the bacterium’s hydrocarbon degradation potential.