Characterization of biosurfactant production by Klebsiella variicola BF1 for hydrocarbon degradation enhancement.

Biosurfactant has an important role in improving hydrocarbon degradation. Klebsiella variicola BF1 is a hydrocarbonoclastic bacteria isolated from hydrocarbon polluted river in Wonocolo Village, Bojonegoro, East Java, Indonesia. Biosurfactant characters are strongly influenced by carbon (C) and nitrogen (N) sources in the medium. This study aims to observe the ability and characters of bacterial biosurfactant. Based on three biochemical tests including hemolysis, oil spreading, and drop collapse test, the bacteria revealed the ability to produce biosurfactant. This biosurfactant characters were investigated by culturing in Bushnell Hass Mineral Salts (BHMS) with a combination of treatments glucose, crude oil, and crude palm oil (CPO), respectively as carbon sources, while urea, NH₄NO₃, and yeast extract as nitrogen sources. The highest emulsion activity of biosurfactant of 66.48 % was analyzed at a combination of treatment urea and CPO. However, the highest yield of crude biosurfactant was 10 ± 2 g/L and cells number was 1.7x10⁸ CFU/mL could be seen in each treatment combination of urea and glucose as well as yeast extract and CPO. Overall, the biosurfactant-producing strain characterized in this research demonstrate promising features for the development of efficiently production processes by inducing CPO and suppressing the cells number in the culture. [ABSTRACT FROM AUTHOR]