BIODEGRADATION POTENTIALS OF AUTOMOBILE WORKSHOP SOIL MYCOFLORA ON FLOW STATION PETROLEUM SLUDGE WITH AN EXTRA CARBON SOURCE

Abstract

The biodegradation potentials of soil mycobiota isolated from six auto mechanic workshops and a farmland in Benin City on flow station crude oil sludge was investigated. Serial dilution and pour plate methods were utilized in the isolation and enumeration of the fungal bioload of the soil samples. The heterotrophic fungal counts ranged from 0.2×103 cfu/g to 3.2×103 cfu/g .Twenty (20) fungal species were identified from the soil samples; Aspergillus flavus, Aspergillus terreus, Aspergillus fumigatus, Aspergillus versicolor, Emericella nidulans, Aspergillus tamarii, Aspergillus niger, Aspergillus sp., Moniliella sp., Pichia farinosa, Sporobolomyces sp., Candida sp., Rhodotorula sp., Curvularia sp., Mucor sp., Rhizopus stolonifer, Penicillium sp. , Penicillium sp.2, Penicillium italicum, and Penicillium chrysogenum. A. flavus and A. nidulans had the highest percentage prevalence (85.7%). Physicochemical analyses revealed that the soil samples were acidic (pH 5.81-6.40) and sandy (50.3%-64.8%). Turbidimeteric screening revealed that A. flavus, A. terrus, Aspergillus sp., Penicillium sp., consortium of yeasts and the filamentous fungal consortium were able to maximally utilize the sludge as the sole source of carbon and energy. The growth profile results obtained for A. flavus revealed a decrease in pH (6.34 – 5.06) and an increase in turbidity (38 FAU – 625 FAU) during the 20 day incubation period. Amongst the growth profile cultures, A. flavuscaused the highest percentage reduction in the residual TPH (DRO) content of the inoculated sludge (96%). Soils within the premises of automobile workshops can serve as a source of hydrocarbonclastic fungi.