Saleh, A., Bala, K. N., Fowowe, S., Abduljalil, N. A. Bature, M., and Tijjani, M. B.
Department of Microbiology, Faculty of Life Sciences, Ahmadu Bello University, Zaria, Nigeria
*Corresponding author’s Email: aliyusaleh1985@gmail.com, doi.org/10.55639/607.020100142
ABSTRACT
Hydrocarbon contamination arising from automobile workshop activities poses significant environmental challenges and necessitates the development of sustainable remediation strategies. This study investigated the physicochemical characteristics of hydrocarbon-contaminated soil from a mechanic workshop in Samaru, Zaria, Nigeria, and evaluated the biosurfactant-producing potential of indigenous bacterial isolates. Physicochemical properties were determined using standard analytical methods. Bacteria were isolated and identified using morphological, microscopic, and biochemical tests. Screening for biosurfactant production was conducted using oil spread and drop collapse assays. Selected isolates were further evaluated for biosurfactant production in mineral salt medium supplemented with 2% (v/v) engine oil as the sole carbon source, and biosurfactant production was assessed through oil spreading and drop collapsed assay. The soil exhibited sandy-loam characteristics with mean values of 77.18 ± 0.06% sand, 12.32 ± 0.03% silt, and 10.57± 0.02% clay. The mean soil temperature, pH, moisture content, CEC, and EC were 28.45 ± 0.21°C, 6.07 ± 0.04, 8.25 ± 0.07%, 9.70 ± 0.28 meq/100 g, and 101.5 μS/cm, respectively. Seven bacterial isolates belonging to five genera were identified; Bacillus spp., Klebsiella spp., Pseudomonas spp., Proteus spp. and Staphylococcus spp. and three of them demonstrated positively for the biosurfactant production potential. Bacillus spp. produced 2.5±0.15 g/L of biosurfactant with an activity of 1.07 ± 0.21 cm oil displacement zone, Pseudomonas spp. produced 2.0±0.06 g/L of biosurfactant with an activity of 6.03 ± 0.15 cm oil displacement zone and Klebsiella spp. produced 1.1±0.12 g/L with 3.10 ± 0.26 cm displacement zone. The findings indicate that hydrocarbon-contaminated mechanic workshop soils harbor indigenous biosurfactant-producing bacteria with potential application in bioremediation.
KEYWORDS
Biosurfactant,
Bacillus spp.,
Klebsiella spp,
Hydrocarbon,
Mechanic
workshop Soil.