Effect of aeration and agitation on the protease production by Staphylococcus aureus mutant RC128 in a stirred tank bioreactor

Abstract

The modified rotating simplex method has been successfully used to determine the best combination of agitation rate and aeration rate for maximum production of extracellular proteases by Staphylococcus aureus mutant RC128, in a stirred tank bioreactor operated in a discontinuous way. This mutant has shown altered exoprotein production, specially enhanced protease production. Maximum production of proteases (15.28 UP/ml), measured using azocasein as a substrate, was obtained at exponential growth phase when the bioreactor was operated at 300 rpm and at 2 vvm with a volumetric oxygen transfer coefficient (K(L)a) of 175.75 h(-1). These conditions were found to be more suitable for protease production.

Production of isomaltooligosaccharides (IMO) using simultaneous saccharification and transglucosylation from starch and sustainable sources

“…Skowronek and Fiedurek used simplex method to optimize five different medium components for production inulinase by Aspergillus niger [20]. The Simplex method has been adopted to find optimal aeration and agitation rates for protease production by Staphylococcus aureus mutant in a stirred tank bioreactor [21]. A rotating simplex method was employed to determine the best suitable fermentation conditions for batch production of chitinase [22].…”

Optimization of Nutritional and Culture Conditions for Improved Protease Production by Aspergillus Nidulans and Aspergillus Flavus

“…In the fermentation process using an aerobic culture, the oxygen affects the production of enzymes due to the changes in the metabolic pathway and metabolic fluxes (Calik et al, 1998). Ducros et al (2009) suggested that the respiration rate of the aerobic culture is dependent on the dissolved oxygen. This is due to physiological alteration in cell metabolism (Hwang et al, 1991).…”

Techniques for oxygen transfer measurement in bioreactors: a review

“…109,110 This method, however, does not give consistent results when compared with the steady-state method of measurement of oxygen uptake rate. The most probable cause of the discrepancy between measurements by the dynamic and steady-state methods is due to the effect of very small gas bubbles in viscous broths.…”

“…Ducros et al 110 determined the k L a values from the transient data of dissolved oxygen obtained during degassing and aeration periods. The probe response was corrected by the first-order lag model.…”