Aromatic Hydrocarbons : Degrading Bacteria in the Desert Soil of Kuwait PDF

Keywords

Kuwait, polluted desert soil, aromatic hydrocarbons, biodegradation, Bacteria

Abstract

Soil samples of different levels of oil pollutants were collected from Kuwait's Burgan Oil Field, near an oil lake. The samples represented, highly polluted (8.0% w/w), moderately polluted (2.1%-3.4%) and slightly polluted (0.5- 0.8%). The aromatic fractions of the collected samples were in the range of (0.21 2.578/100g) soil (GC) analysis of the aromatic fractions for the resolution of the different individual (PAH) revealed the presence of (16) different (PAH) resolved from the aromatic fraction of the highly polluted sample (53). (15). (14) and (13) individual (PAH) were identified from soil samples (55), (52) and (S1, S4, S6) respectively The most frequent (PAH) was indeno (1.2.3-c.d) pyrene (22.5%-45.11%) followed chrysene (13.6%-19.48%). Eight carcinogenic (PAH) were resolved from the aromatic fractions of the polluted samples. Total carcinogenic (PAHs) recorded in this study were the range of (11.53) (for S4) - (510.98) (for $3) ppm. The counts of (CFU) of aromatic degraders (AD) were in the range of (3 x 10)-(110 x10") (CFU/g) soil (with a percent of (2.2%-69.6%)). The results show that, higher counts of (AD) were recorded from the highly polluted sample (3), followed by the moderately polluted samples, total of (51) bacteria, that gave presumptive positive biodegradation activities, were isolated and identified. (45.1%) of them were isolated from the highly polluted sample (53) . Total of (13) different species were identified of which Micrococcus luteus was more frequent (23.5) followed by Bacillus licheniformis (19.6%) and Bacillus subtilis (11.8%). The three Pseudomonas species collectively were represented by (11.8%). Five different species proved to be of good activities, they are Bacillus brevis, Bacillus licheniformis, Pseudomonas aeruginosa, Pseudomonas starteri and Pseudomonas fluorescents The ability of the five species and their mixture was investigated. The three Pseudomonas spp were able to degrade more (PAHs) than the Bacillus spp. On the other hand the mixed culture showed high biodegradation activities (88.6%) as compared to the pure individual cultures