Production of biosurfactants by Bacillus licheniformis and Candida albicans for application in microbial enhanced oil recovery

In this study, the bacterium Bacillus licheniformis DSM = 13 strain ATCC 14580 and the yeast Candida albicans IMRU 3669 were used for biosurfactant production. Surface properties of the produced biosurfactants were confirmed by determining the emulsification power as well as surface tension. The crude biosurfactants have been extracted from supernatant culture growth. FTIR analysis confirmed the chemical structure of the produced biosurfactants. The yields of crude biosurfactants were about 1 and 12 g/l for B. licheniformis and C. albicans respectively. Also, the results revealed that the emulsification power has been increased up to 96% and 65% with kerosene for bacterial and yeast strain respectively. Surface tension decreased from 72 to 36 mN/m after 72 h of incubation with B. licheniformis and 45 mN/m after 4 days of incubation with C. albicans. The potential application of this bacterial species in microbial enhanced oil recovery (MEOR) was investigated. The percent of oil recovery were 16.6 and 8.6 wt% for the bacterial and yeast strains respectively, upon application in sand pack column designed to stimulate an oil recovery.