Factors affecting l-arginine production in the continuous culture of an l-arginine producer of Corynebacterium acetoacidophilum

Abstract

The effects of culture conditions on l-arginine production by continuous culture were studied using a stable l-arginine hyperproducing strain of Corynebacterium aceto-acidophilum, SC-190. Strain SC-190 demonstrated a volumetric productivity of 35 g l −1·h −1 at a dilution rate of 0.083h −1 and feeding sugar concentration of 8%, and a product yield of 29.2% at a dilution rate 0.021h −1 and feeding sugar concentration of 15%. The corresponding values for fed-batch culture are 0.85 g· l −1·h −1 and 26%. However, the product yield decreased with an increase in the volumetric productivity. To achieve stable l-arginine production, aeration and agitation conditions sufficient to maintain an optimal level of redox potential (>−100 mV) were necessary. The addition of phosphate to the feeding medium led to a decrease in l-arginine production. It was confirmed in the steady state that growth and l-arginine formation were inhibited by a high concentration of l-arginine.