Detection of Methane-Oxidizing Bacteria and their Use in Petroleum Hydrocarbon Removal

Methylotrophic bacteria have been identified as using carbon one (C1) compounds such as methane. In recent decades, the priority has been on determining new genera of bacteria that have the capability to consume methane and mitigate the effects of global warming. In order to isolate methane-oxidizing bacteria, oil polluted soil samples were collected from Mushrif gas station in Basrah Governorate/southern Iraq. The analysis of 16srRNA genes identified Paenibacillus sp. and Paenibacillus lautus, which were able to consume methane as its sole carbon source in NMS medium, also detect the pMMO gene (encoded methane monooxygenase enzyme) by real-time PCR. AS far as we know, P. lautus was found for the first time to consume methane as a sole carbon and energy source. These bacteria were able to exploite crude oil as their sole source of carbon and energy, recorded the highest growth for Paenibacillus sp and P. lautus at 1.9 and 0.5 (OD600) after 5 days of incubation successively. The results of gas chromatography analysis revealed high degradation of these bacteria for aliphatic compounds, reaching 92.8% and 89.41% for Paenibacillus sp. and P. lautus, respectively. Additionally, they exhibited high rates of degradation of aromatic compounds at 98.8% and 97.28%, respectively.