Effect of biosurfactant sophorolipids on Rhizomucor miehei lipase fermentation by Aspergillus oryzae

Abstract In this study, the effect of biosurfactant sophorolipids (SLs) on Rhizomucor miehei lipase (RML) fermentation by Aspergillus oryzae was investigated. With exogenous addition 0.3% (w/v) SLs in initial medium, RML activity reached 430.0 U/mL, an increase 25.0% compared to control group. Subsequently, physiological metabolic responses A. were further explored. The results showed that though had almost no secretion, it would affect morphology cells. During late phase fermentation, proportion middle pellets, which generally considered as energetic and stable state for enzyme production increased with SLs. Simultaneously, viscosity broth reduced, facilitated oxygen transfer, thereby improving production. Finally, could be found significantly contents precursor amino acids, especially those rank first second composition, promote synthesis RML.