Optimization of Surfactin Production by Bacillus subtilis NLIM 0110 in Shake Flask

In this research, biosurfactant production (surfactin) by Bacillus subtilis NLIM 0110 has been investigated. This microorganism was isolated from agricultural area of Iran. For surfactin production, the best condition of biosurfactant in shake flask was obtained at 37°C and 250 rpm. In this condition, maximum production of biomass and biosurfactant are 4 and 1.8 g/L. The yield of biosurfactant on biomass (Yp/x), biosurfactant on sucrose (Yp/s), and the volumetric production rate (Y) for shake flask were obtained about 0.45 g/g, 0.18 g/g, and 0.03 g/L.h, respectively. For this microorganism, the production of biosurfactant was proportional to the cell growth representing biosurfactant as a growth-associated product. The produced surfactin showed good surface activity because it is able to reduce the surface tension from 72 mN/m to 25 mN/m. Therefore, the proposed biosurfactant is appropriate candidate for industrial applications.