CHARACTERIZATION OF BIOSURFACTANT PRODUCED BY BRUCELLA INTERMEDIA AND STUDY OF ITS BIOREMEDIATION AND ANTIMICROBIAL POTENTIAL

Abstract

Crude oil contamination poses significant environmental challenges due to its complex mixture of hydrocarbons and organic compounds. Oil spills in soil disrupt plant growth, harm microorganisms, kill soil fauna, and contaminate water, leading to habitat loss and environmental degradation. Many bacteria are known for their potential to synthesize biosurfactant sand sustainably remediate hydrocarbon pollution. This study aimed to isolate a potential biosurfactant producing strainfrom environmental samples, optimize the nutrient and physicochemical conditions for its yield, and characterize the biosurfactant type. In addition, the antimicrobial and Microbial Enhanced Oil Recovery (MEOR) potential was also studied using well diffusion assay and sand pack column, respectively. Among the 31 isolates, Brucella intermedia was identified as the most potent strain with emulsification value of 45%. It reduced surface tension of garage oil by 37.5%. Optimum yield was obtained in media with 6%inoculum, pH 7.2,containing 4%garage oil,0.5% tryptone and 0.3% potassium nitrate, and incubation at 30°C under shaker conditions for 48 h. Optimum biosurfactant recovery was obtained with chloroform:methanol (2:1). The crude biosurfactant contained 2.345 mg/mL carbohydrate, 1.81 mg/mL proteins and 35.77% lipids. FTIR analysis revealed key functional groups that highlight the amphiphilic nature of the biosurfactant. Studies on the antimicrobial potential of the biosurfactant indicated broad spectrum activity, with more prominent effect against Gram positive bacteria. It also recovered 65%used garage oil and 50% mixed vegetable oil, indicating its potential in MEOR. Overall, the biosurfactant producing B. intermedia strain is a potential candidate for industrial applications in the biological and environmental fields.