Phylogenetic analysis of hydrocarbon degrading bacteria associated with crude oil polluted soil from Mesogar community, Delta State, Nigeria

Abstract

This study was carried out to isolate hydrocarbon-degrading bacteria associated with oil polluted soil samples collected from Mesogar community of Delta State, Nigeria. The samples were aseptically collected and the bacteria isolated according to standard microbiological techniques. The isolates with hydrocarbon biodegradative ability were screened on MSM supplemented with 2% crude oil using spectrophotometric method. The amount of crude oil degraded by the highest hydrocarbon degrader was determined using gas chromatographic (GC) assay. A total of seven bacterial isolates were molecularly identified using the 16S rRNA gene sequencing method. The sequences were compared to those deposited in NCBI using the basic local alignment tool (BLAST) algorithm. Phylogenetic analysis of 16S rRNA gene sequences was carried out to determine the evolutionary relationships of the isolated bacterial species. The isolates were identified to have remote similarities with Alcaligenes faecalis SH179a, Alcaligenes faecalis subsp. Phenolicus, Bacillus thuringiensis serovar konkukian, Ochrobactrum anthropi, Alcaligenes faecalis SH179b, Uncultured soil bacterium clone and Alcaligenes faecalis IVN45. Strain OFBR 4 had the highest degrading ability. The use of molecular methods for rapid and accurate detection of diverse strains of hydrocarbon-degraders is of utmost necessity in bioremediation.

Keywords: Phylogenetic analysis, oil polluted soil, biodegradative, hydrocarbon degrader, 16S rRNA gene and crude oil.