ydrocarbon Utilization and Bioremediation Potential of Bacteria Isolated from Lemna Waste Dumpsite Leachates, Calabar, Nigeria 0 0
Keywords:
Hydrocarbon degradation, Bioremediation, Leachate, Dumpsite, Pseudomonas aeruginosaAbstract
Hydrocarbon pollution remains a significant environmental problem, especially in developing regions with inadequate waste management systems such as Nigeria. This study evaluated the hydrocarbon utilization and bioremediation potential of bacteria isolated from Lemna waste dumpsite leachates in Calabar, Nigeria. Leachate samples were collected aseptically and analyzed using serial dilution and enrichment culture techniques on Mineral Salt Medium supplemented with crude oil as the sole carbon source. Isolates were identified through morphological, biochemical, and molecular methods, including 16S rRNA gene sequencing and phylogenetic analysis. Results showed that the leachate supported diverse hydrocarbon-utilizing bacteria, predominantly Pseudomonas aeruginosa, Chromobacterium violaceum, Micrococcus luteus, and Bacillus subtilis. Growth performance analysis revealed high optical density values for Pseudomonas aeruginosa (1.92 ± 0.12) and shorter lag phase compared to other isolates. Hydrocarbon utilization efficiency increased over time, reaching up to 88% in Pseudomonas aeruginosa. Emulsification index (E24) values were highest in Pseudomonas aeruginosa (82% in kerosene and 78% in crude oil), indicating strong biosurfactant production. Molecular screening confirmed the presence of hydrocarbon degradation gene (alkB) and biosurfactant genes (rhlA and rhlB) in Pseudomonas aeruginosa, while phylogenetic analysis showed 97–99% similarity with reference strains. The study confirms that Lemna dumpsite leachates serve as reservoirs of highly active hydrocarbon-degrading bacteria with strong genetic and functional capabilities. These findings highlight the potential of indigenous microbial strains for sustainable bioremediation of petroleum-contaminated environments.
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