Petroleum hydrocarbon degrading capability of freshwater autochthonous filamentous fungi

Abstract

Petroleum hydrocarbon degrading capability and growth profile of indigenous filamentous freshwater fungi from four (4) different streams were determined in vitro. The result indicated that the streams under investigation contained an average heterotrophic fungal count of 5.55 0.25x105 cfu ml-1 while the mean count of biodegraders of Qua Iboe light crude oil after 15 days of incubation was 3.170.21 x 104 cfu ml-1. The best four utilizers of petroleum hydrocarbons for carbon and energy isolated from the streams were Aspergillus-OUF7, Rhizopus-OUF8, Aspergillus-OUF11 and Fusarium-OUF14. The growth profile of the fungi on oil medium showed that the isolates have an average total viable count (TVC) of 16% after an incubation period of 35 days, hence their ability to utilize Qua Iboe light crude oil efficiently. The isolates equally demonstrated a high degree of crude oil degrading potentials with an average percentage weight loss of 92%, 78% and 55% after 35days of incubation on 1%, 5%, 10% pollution levels on Qua Iboe light crude oil respectively. The percentage weight loss among the test isolates showed a positive correlation between pollution levels and varied significantly (p<0.05) over incubation period. The results therefore suggest that systematic bioremediation involving these autochthonous freshwater fungi can be effectively utilized over a period in remediating considerable levels of crude oil pollution in a freshwater ecosystem within the Niger Delta region of Nigeria.

Global Journal of Environmental Sciences Vol. 6 (1) 2007: pp. 33-40