EFFECT OF CARBON:NITROGEN AND DISSOLVED OXYGEN ON THE BIOSURFACTANTS PRODUCTION FROM Bacillus subtilis

Abstract

The aim of the present study was to find the effect of the Carbon and Nitrogen (C:N) ratio and dissolved oxygen (DO) concentration on biosurfactant production at flask and reactor level respectively. The biosurfactants production from Bacillus subtilis was evaluated by superficial activity in supernatant as well as biological activity of supernatant freeze dried at different times. It was rated the C:N ratio 2.6, 5.7, 8 and 11.6, being the cultures with C:N ratio 8 and 11.6 with 6 and 7 respectively of superficial activity and that showed hemolytic activity and antimicrobial activity against Saccharomyces cerevisiae and Fusarium. In the case of DO in batch culture, it was rated C:N ratio 8 and 11.6, the lipopeptide production at a high level of DO was 17.26 g l-1 and 14.79 g l-1 respectively in comparison with the low level of DO with 7.96 g l-1 and 2.21 g l-1. The C:N ratio 8 and 11.6 at high level of DO were favourable to produce lipopeptides with surface activity.