The effects of carbon and nitrogen sources on biosurfactant fermentation by Ochrobactrum intermedium XY-1

Abstract

Carbon and nitrogen source is very important for biosurfactant production. In this paper, we investigated the influence of carbon sources and nitrogen sources on biosurfactant production by Ochrobactrum intermedium strain XY-1 by determining the cell density, as well as the surface tension and the emulsifying activity of culture broth. The results showed that Ochrobactrum intermedium strain XY-1 achieved higher biosurfactant yields with sucrose as a carbon source (10 g/L) , sodium nitrate as a nitrogen source (4 g/L), and at a carbon to nitrogen ratio of 10:1, the highest emulsifying activity of fermentation supernatant to liquid paraffin was as high as 55%. The tested strain could grow and produce biosurfactants by utilizing potassium nitrate similar to sodium nitrate, maltose inferior to sucrose, and at a carbon to nitrogen ratio of 20:1 or 30:1 similar to 10:1, but could not utilize hydrocarbon carbon source and urea nitrogen source well.