Experimental investigation of molasses as a sole nutrient for the production of an alternative metabolite biosurfactant

In this study, sugarcane molasses was explored as a sole source of nutrients for the production of a value added product (biosurfactant) using an isolated strain Bacillus subtilis RSL-2. The biosurfactant production (maximum) was scrutinized by response surface methodology-central composite design (RSM-CCD), considering molasses as the carbon source (1-5 % w/v), pH (4-8) and temperature (25-45 degrees C), as the input parameters. At the optimized condition, remarkable biosurfactant concentration and surface tension were obtained as 12.34 +/- 0.1 g/L and 24.09 +/- 0.11 mN/m, respectively. The critical micelle concentration of the produced biosurfactant was found to be 80 mg/L. The produced biosurfactant was identified to be lipopeptide in nature and reduced the surface tension of water from 72.80 +/- 0.5 mN/m to 24.09 +/- 0.11 mN/m. The produced biosurfactant showed excellent surface activities, and thermal and colloidal stability. The present study endorsed the suitability of molasses as a suitable substrate (media) for the remarkable production of biosurfactant.