Diversity and hydrocarbon degradative potential of endophytic bacteria isolated from Hibiscus cannabinus and Zea mays grown on crude oil-polluted soil from Egbema, Nigeria

• Phytoremediation of crude oil-polluted soil from Egbema Nigeria • Bacteria endophytes (57) were isolated from roots of Hibiscus cannabinus and Zea mays • Endophytic bacteria utilized n-alkanes and diesel as sole carbon source • Bacteria isolates possessed alkane monooxygenase genes • Diversity analysis revealed class β-proteobacteria, γ-proteobacteria and δ-proteobacteria Environmental pollution as a result of anthropogenic activities has resulted in detrimental effects of global concern. The recent call for the use of non-chemical substances in pollution control led to the concept of phytoremediation. Asymptomatic associations between microbes and their host plants have been implicated to offer more efficient remediation processes. Hibiscus cannabinus and Zea mays grown on crude oil-polluted soil from Egbema Nigeria were analysed for the endophytic bacteria community resident therein. Out of the total 57 endophytic bacteria isolated, 24 isolates were selected for molecular studies based on their plant growth-promoting properties. Endophytic bacteria isolates were tested for their ability to utilize n-alkanes (C 6 , C 8 and C 10 ) and diesel oil as carbon sources in the absence of glucose. The presence of hydrocarbon degradative genes in isolates was detected by amplification using Alk B primers. The 16s rDNA region of the isolates was amplified and the sequenced amplicons were compared against other bacteria genomes. Our study revealed the hydrocarbon degradative ability of isolated endophytic bacteria. In addition, isolates possessed alkane monooxygenase genes responsible for hydrocarbon degradation in bacteria species. Moreover, diversity analysis revealed class β-Proteobacteria, γ-Proteobacteria and δ-Proteobacteria as endophytic bacteria communities within Hibiscus cannabinus and Zea mays . The ability of endophytic bacteria isolates to grow on diesel oil and n-alkanes served as an indication of the potential application of the isolates in bioremediation activities.