One of the obstacles in the way of wide scale industrial application of biosurfactants is the high production cost coupled with a low production rate. In order to lower the production cost surfactin production by Bacillus subtilis MTCC 2423 was studied in submerged batch cultivation using waste frying oils. It was observed that the decrease in surface tension was 56.32%, 48.5% and 46.1% with glucose, waste frying sunflower oil and waste frying rice bran oil, respectively. Biomass formation was 4.36 g/L, 3.67 g/L and 4.67 g/L for glucose, waste frying sunflower oil and waste frying rice bran oil, respectively. Product yield (g product/g substrate) was 2.1%, 1.49% and 1.1% with glucose, waste frying sunflower oil and waste frying rice bran oil as substrates. This process facilitates safe disposal of waste frying oil, as well reducing the production cost of surfactin.
Biosurfactants; Bacillus subtilis; Surface Tension; Waste frying oils; Secondary metabolite
