A Comparative Study On The Biodegradation Of Crude Oil By Bacterial And Fungal Isolates:- Awujo, Odinakachii

ABSTRACT

A comparative study on the rate of biodegradation of crude oil contaminated soil by bacterial and fungal isolates were carried out using gravimetric analysis. The bacterial and fungal genera that were used for the comparative studies were Pseudomonas and Bacillus, Penicillum and Aspergillus respectively. The amount of crude oil degraded was monitored for 56 days by the measurement of total hydrocarbon utilizing bacteria and fungi and some physio-chemical parameters. The growth pattern of the isolates showed that Pseudomonas sp. had the highest growth with counts of 5.9 x 106 cfu/g during the period ofmonitoring. This was followed by Bacillus sp. (4.4 x 106 cfu/g) and Aspergillus sp. (4.3 x 106 cfu/g). Penicillium sp. (2.9 xlO6 cfu/g) had the least growth in the polluted soil for hydrocarbon utilizing bacteria and fungi. There were differences in the physio-chemical analysis from the soil samples which showed the process of degradation. The highest Total Organic Carbon (TOC%) reduction was achieved by Pseudomonas sp.(15.07%) after 56 days incubation period followed by Bacillus 5/?. (20.4%). There was a significant difference in the utilization ofBonny light crude oil by the isolates with time when tested with ANOVA at P< 0.05. Pseudomonas sp. had the highest degradation rate of 49.9% whereas Bacillus sp., Aspergillus sp. and Penicillium sp. had degradation rates of 43.30%, 36.33% and 34.17% respectively. The control showed the lowest degradation rate. Comparatively, the bacterial species (Pseudomonas sp. and Bacillus sp.) degraded the crude oil was monitored for 56 days by the measurement of total hydrocarbon utilizing bacteria more efficiently than the fungal species (Penicillium sp. and Aspergillus sp.)