Isolation of Bacillus Licheniformis and Bacillus Subtilis from Gachsaran and Cheshmeh khosh petroleum reservoirs and optimizing their growth

In order to investigate the potential of applying microbial enhanced oil recovery technique in Iran, bacterial isolation was carried out from crude oil samples of Gachsaran and Cheshmeh Khosh petroleum reservoirs. The ability of isolates to produce biosurfactant was checked by specific culture media. Isolates were also cultured in media enriched by different carbon sources and evaluated their growth curve after 7 days to determine the optimum growth condition of them. The most effective nutrients were whey, starch and soybean water. Finally isolates were characterized by conventional biochemical tests and two isolate with the highest performance were selected for molecular characterization. The nucleotide BLAST similarity search analysis, based on the 16S DNA gene sequence revealed that these isolates belong to Bacillus subtilis (JN0335542) and Bacillus licheniformis (JN0335541).