Bioremediation of Bonny light crude oil polluted soil by bioaugmentation using yeast isolates (Candida adriatica ZIM 2468 and Candida taoyuanica MYA-4700)

Abstract

The elimination of a wide range of pollutants and wastes from the environment is an absolute requirement to promote a sustainable development of our society with low environmental impact. The focus of this study is to remediate, monitor the progress of bioaugmentation in a hydrocarbon polluted soil using yeast isolates and to highlight the needs for integration of laboratory data to full scale in situ bioremediation. In this study, yeast isolates were used to bioaugment Bonny light crude oil polluted soil in Niger Delta. Yeast isolates used were Candida adriatica ZIM 2468 and Candida taoyuanica MYA-4700. The indigenous fungal isolates identified from the soil were species of Alternaria, Aspergillus, Fusarium, Mucor, Penicillium, Rhizopus, Trichoderma, Candida, Rhodotorula and Saccharomyces. One kilogram of fresh soil sample was polluted with crude oil (10%). Physico-chemical analysis was carried on the fresh soil before and after pollution. Candida adriatica ZIM 2468, Candida taoyuanica MYA-4700 and a consortium containing both isolates were inoculated into the different microcosms to increase the number of microorganisms. At every fourteen days, samples were analyzed for total petroleum hydrocarbon (TPH) and microbial counts were carried out. Total petroleum losses of 84.6% (A – consortium of Candida adriatica ZIM 2468 and Candida taoyuanica MYA-4700), 77.3% (B – Candida adriatica ZIM 2468), 73.4% (C – Candida taoyuanica MYA-4700) and 28.7% (Control – unamended) were recorded in the bioaugmentation set-up, respectively at day 56. On the whole, amending with both Candida species proved to be more effective in hydrocarbon

Keywords: Bioaugmentation, hydrocarbons, yeast species, Niger Delta