Standardization of biosurfactant enrichment process by factorial design and elucidating its physico-chemical and structural characteristics

Biosurfactant recovery by Flavobacterium sp. was standardized by factorial design 3(k-p). The extraction of biosurfactant was carried out by organic solvent extraction, ammonium sulphate precipitation and acid precipitation. The organic solvent extraction was performed with varied proportion (3 levels) of chloroform and methanol i.e. (X*:1) designated as F1 (varied proportion of chloroform) and (1: X**) referred as F2 (varied proportion of methanol) respectively, similarly ammonium sulphate (F3) and acid precipitation (F4) was performed with 3 varying experimental level. The statistical data interpretation viz ANOVA, Pareto chart of standardized effect, Half normal probability plot inferred  organic solvent extraction as a efficient method for recovery of biosurfactant, than other counter parts of extraction .The surface plot between significant factors, given the standardized proportion of organic solvents for extraction of biosurfactant, which was found to be 1:1. Surface tension and CMC value of recovery biosurfactant was found to be 33 mN/m and its CMC was 400- 500mg respectively, it has shown maximum emulsification index of 94% for soyabean oil. The presence of glycolipid moiety in the recovery biosurfactant was elucidated by IR and NMR spectroscopic studies.   Keywords: Factorial design, organic solvent, CMC, Emulsification index