Naturally-occurring microbial consortia for the potential bioremediation of hydrocarbon-polluted sites in Trinidad

Methods to improve the efficiency of bioremediation of hydrocarbon-contaminated sites involves the assessment of microbial consortia in culture. In the present study, the cooperative capabilities of indigenous bacteria, yeast and fungi, as naturally-occurring consortia isolated from chronically contaminated sites in Trinidad, were screened to determine the most efficient associations that resulted in maximum oil clearance. Thirty naturally-occurring consortia involving both known biosurfactant-producing and non-producing isolates were screened. A total of sixteen combinations of yeast with fungi and bacteria with fungi were found to be the most efficient at crude oil deterioration based on >70% a zone of clearance around the original inoculum site on different media. The study revealed a difference in degradation action of strain-specific combinations which confirmed that the development of microbial consortia is both strain- and site-specific. Those consortia composed of biosurfactant-producing members were the most efficient at crude oil removal.