ABSTRACT
This comprehensive study offers an in-depth exploration of the capacity of bacterial isolates to effectively utilize crude oil in soil contaminated with petroleum product. These bacterial isolates were sourced from the proximity of a gas flaring site situated at the Oredo Flow Station in Ologbo, Edo State, Nigeria
The study's critical findings highlighted the proficiency of microbial consortia in degrading Total Petroleum Hydrocarbon (TPH) compared to individual isolates. The microbial consortia ABCD exhibited the highest TPH degradation potential (78.7%) after 28 days. The study presents a four-week shake flask degradation experiment assessing the biodegradation capabilities of individual bacterial isolates (Acinetobacter sp., Bacillus cereus, Bacillus sp., Pseudomonas aeruginosa) and their consortium (ABCD) in degrading petroleum hydrocarbon in the medium. The experiment monitored optical density (turbidity), pH, and bacterial count over the weeks. In week one, pH ranged from 7.1-7.2, while viable bacterial counts ranged from 60×103 to 170×103 cfu/ml. Optical density ranged from 0.063 to 0.307 ntu. In week two it was observed that pH increased to 7.5, with bacterial counts ranging from 5×104 to 42×104 cfu/ml and optical density from 0.115 to 1.004 ntu. In week three, the pH reduced from 7.0- 6.5, the bacterial counts ranged from 9.66×105 to 49.62×105 cfu/ml, and optical density ranged from 0.4 to 1.401 ntu. In week four, the consortium (ABCD) exhibited the highest degradation potential, with optical density of 2.118ntu. The pH dipped from 6.5-6.2 with a corresponding increase in viable bacterial counts (14.33×106 to 46.33×106 cfu/ml). The biodegradation of Total Petroleum Hydrocarbon (TPH) was also assessed, with the consortium (ABCD) showing the highest degradation at 78.7% after 28 days.
Figure4. highlighted the degradation of Total Petroleum Hydrocarbon (TPH), illustrating that consortium's enhanced efficiency in TPH degradation over individual isolates, with degradation rates of 78.7%, 76.8%, 70.4%, and 68.7% for ABCD, BD, AD, and AC, respectively. These findings underscore the significance of consortium interactions and their potential in enhancing hydrocarbon biodegradation, paving the way for more effective bioremediation strategies in petroleum-contaminated environments.
