Isolation and characterization of biosurfactant producing bacteria from Mile 2 and Ologe Lagoons, Nigeria

ABSTRACT

Aims@#This study was aimed to isolate and characterize biosurfactant producing bacteria from Mile 2 and Ologe Lagoon which are sinks for domestic and industrial waste waters and potential source of value added bioresources such as biosurfactants, hydrocarbon degraders and organisms with potential for biotechnological applications.@*Methodology and results@#Physicochemical parameters of the two lagoon waters were analyzed using standard procedures. Bacteria were isolated using enrichment techniques on 1% Escravos light crude oil, palm oil and groundnut oil on mineral salt medium (MSM). Biosurfactant production by the isolates was assayed by hemolytic activity, oil spread test, blue agar test and emulsification activity. Isolates were identified using their colony morphologies and biochemical characteristics, while the antibiotic susceptibility of the isolates was determined using multidisc. The physicochemistry of the lagoon water showed high nitrate content of 15.7 mg/L and 19.6 mg/L for Mile 2 and Ologe Lagoon, respectively. Total hydrocarbon content (THC) of both lagoon waters was low, with values 0.53 mg/L for Mile 2 Lagoon and 0.44 mg/L for Ologe Lagoon. The predominant genera of bacteria identified include Micrococcus, Bacillus, Pseudomonas, Acinetobacter, Stomatococcus and Moraxella. A total of 23 bacterial isolates were tested for hemolytic activity, of which 13 showed β-hemolysis which is presumptive for biosurfactant production, 5 showed α-hemolysis and the remaining 5 exhibited γ-hemolysis. Majority of the isolates were positive for oil spread assay and blue agar test (19) indicating production of anionic biosurfactant. The isolates showed good emulsification activity; AGG3 (67.7%), AGG1 (62.3%), AGG2 (60%), AGG4 (60%), MTP2 (56%), AGC4 (54%) and the least emulsification value of 23.3% for strain AGP1. Most of the isolates were susceptible to ciprofloxacin, perfloxacin and showed resistance to septrin and erythromycin.@*Conclusion, significance and impact of study@#This study showed that Mile 2 and Ologe Lagoon are a potential source of biosurfactant producers with diverse emulsification properties and prospective industrial applications. This would have implication for economic empowerment, as well as sustainable and environmentally friendly clean-up technology in both locally and globally.