Bioreactor design for enhanced surfactin production with Bacillus subtilis NLIM 0110

Biosurfactants are widely used in industries like oil، cosmetics، food، and pharmaceutics. Surface tension reduction، the ability to emulsify oil and high biodegradability are among the main characteristics of these biosurfactants. These favorable features make biosurfactants as potential alternatives of chemically synthesized surfactants in a variety of applications. In this research،Bacillus subtilis NLIM0110 was used to produce a lipopeptide-type biosurfactant (surfactin) in an innovative bioreactor tailored to solve the problems of severe foaming arising from production of the biosurfactant. To cope with the rapid foam generation، a conventional fermentor was integrated with a foam collector. The other aims of this study were purification، identification of surfactin، optimization of agitation rate and aeration rate which were used to increase the surfactin production. The results showed the production of biosurfactant was proportional to the cell growth representing biosurfactant as a growth-associated product. The best condition for bioreactor was 300 rpm and 1. 5 vvm، giving Yp/s، Yp/x and Y of 0. 595 gg−1، 0. 25 gg−1، and 0. 057 gl−1h−1، respectively. The production of surfactin was confirmed by FTIR and HNMR analysis. Thus، these results show the potential effectiveness of the microorganism and the technique used in biosurfactant production.