Production of Biosurfactant Using Bacillus subtilis Natto Fermentation

Biosurfactants are microbial amphiphiles produced as primary metabolites by varieties of microorganisms. They are preferred over chemically derived surfactants owing to their intrinsic properties, such as superior environmental compatibility, biodegradability, anti-inflammatory and antimicrobial activity, and higher tolerance towards extreme environmental conditions such as temperature, salinity, and pH levels. However, commercial production of biosurfactants is still lacking. The main reason for this is the low yields obtained from fermentation processes, which causes them to be unable to compete compared to chemical surfactants. The present study conducted a one-factor-at-a-time (OFAT) analysis on fermentation conditions to enhance biosurfactant yield from a probiotic strain, Bacillus subtilis Natto. The fermentation was conducted by varying parameters such as nitrogen source, vegetable oils, inoculum size, amino acids, and pH of the fermentation medium. Results showed a significant improvement of 45% in biosurfactant production from B. subtilis Natto when the initial pH of the fermentation medium was adjusted to pH 6.8, urea as the nitrogen source, inoculum size of 6% v/v and the addition of palm olein at a concentration of 2% v/v as a substrate in the fermentation medium.