BIOCHEMICAL STUDIES ON SOIL ENZYME ACTIVITIES AND PLANT GROWTH UNDER MYCOREMEDIATION USING Penicillium roqueforti FOR CRUDE OIL CLEANUP

Abstract

One of the major environmental problems today is hydrocarbon contamination resulting from the activities related to the petrochemical industry. Hence, there is a need to remediate polluted sites to avert its adverse consequence on the environment. In this study, the effect of crude oil pollution and mycoremediation using Penicillium roqueforti on soil health and plant growth was investigated. Five kilogram of sieved soil was weighed and put into 21 labelled pots. Pots containing soil samples were polluted with crude oil at various concentrations (0.1, 0.5 and 1.0% w/w of soil). Five percent (v/v) of fungal culture (Penicillium roqueforti) was used to remediate the polluted soil. Tomato (Solanum lycopersicum) and okra (Abelmoschus esculantus) were planted on all soil samples to assess the effect of treatment on plant growth. All soil samples were kept in the screen house for 90 d. Enzyme (catalase, β-glucosidase, dehydrogenase, urease, acid and alkaline phosphatase) activity in soil samples and physical parameters (height, number of leaves and girth) of planted crops were monitored at 15 d intervals over 90 d period. At 45 d, urease activity in soil samples on which okra was planted was 5.65±0.0098 U/g soil, 4.086±0.0045 U/g soil and 5.99±0.0035 U/g soil for clean (unpolluted) soil, soil polluted with crude oil (1% v/w) and soil polluted with crude oil (1% v/w) that was subjected to mycoremediation using P. roqueforti, respectively. The results indicated that P. roqueforti mitigated the effect of crude oil pollution on soil enzyme activity and plant growth. Gas chromatography-mass spectrometry (GC-MS) analysis of soil samples after 90 d showed crude oil was degraded by P. roqueforti. The ability of P. roqueforti to degrade crude oil and improve soil enzyme activity and plant growth make it a good bioresource for mycoremediation of crude oil polluted sites.