ENHANCED BIODEGRADATION OF PAHs USING BIOSURFACTANT PRODUCING BACTERIA FROM A HUMIC FRESHWATER ECOSYSTEM OF ENIONG RIVER, ITU-NIGERIA
JOSEPH ESSIEN
Microbiology Research Unit, International Centre for Energy and Environmental Sustainability Research (ICEESR), University of Uyo, Uyo, Nigeria.
EDU INAM
Chemistry Research Unit, International Centre for Energy and Environmental Sustainability Research (ICEESR), University of Uyo, Uyo, Nigeria.
NSIKAK ABRAHAM *
Microbiology Research Unit, International Centre for Energy and Environmental Sustainability Research (ICEESR), University of Uyo, Uyo, Nigeria.
GODWIN UDOFIA
Microbiology Research Unit, International Centre for Energy and Environmental Sustainability Research (ICEESR), University of Uyo, Uyo, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This study on enhanced biodegradation of polycyclic aromatic hydrocarbons using biosurfactant producing bacteria from a humic freshwater ecosystem was carried out using standard analytical procedures. Screening for biosurfactant producing potentials of the bacterial isolates using hemolytic test, oil spread, drop collapse and emulsification capacity test revealed 4 biosurfactant producing bacterial strains with Micrococcus luteus being the best biosurfactant producer. This potential was also discovered to be plasmid mediated as well as enhance the crude oil and PAH degrading potential of Bacillus subtilis by 46.06% as against 19.65% obtained when degraded by Bacillus subtilis alone. The results also revealed a greater than 90% selective degradation of naphthalene anthracene, benzo(a)pyrene, acenapthylene, benzo(a)anthracene, fluorene, acenapthylene, acenapthene, benzo(b)fluoranthene and pyrene. Most degraded PAHs suite were Naphthalene followed by anthracene, benzo(a)pyrene, acenapthylene and benzo(a)anthracene. The potentials of these bacterial communities can be explored for broader use in remediating crude oil-polluted environment and farmlands, a condition which is inherent and of high concern in the oil-producing Niger Delta region of Nigeria.
Keywords: Biodegradation, biosurfactant, PAH, plasmid, Bacillus, Micrococcus