Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Optimization of Environmental Parameters for Biosurfactant Production by Bacillus thuringiensis

R.C. Jaysree, Jyothi Patel and N. Rajendran*

Molecular and Microbiology Research Lab., Environmental Biotechnology Division, School of Bio Sciences and Technology, VIT University, Vellore - 632014, India.

Received on 30 November 2014 and accepted on 15 January 2015



Biosurfactants are biological compounds produced by microorganisms such as bacteria, yeasts and fungi etc. on the cell surface or extracellularly. Biosurfactants are used in agriculture, and industry such as detergent, cosmetics, paper etc., and it has enlarged its significance for its large production. In the present study, Bacillus thuringiensis (JB) was used to optimize at different environmental parameters such as pH (6 to 9), NaCl concentrations (1 to 4 %) and water soluble fraction (WSF 1 to 4%) concentrations to maximize the production of biosurfactant. Culture samples were drawn and assayed for biomass, emulsification activity and biosurfactant production for 5 days. It showed maximum activity and yield at pH 7 and 3 and 4 % of NaCl. 3% WSF showed good activity whereas 4% WSF provided good yield of biosurfactant. Bacillus thuringiensis showed good growth, activity and yield during the optimized environmental conditions of the bacteria.

Keywords : Biosurfactant, Bacillus thuringiensis, biodegradation, optimization, diesel, water soluble fraction.