An improved temperature-triggered process for glutamate production with Corynebacterium glutamicum

An improved glutamate-producing fed-batch process, using a temperature-sens itive strain of Corynebacterium glutamicum, has been characterized. By a ti ght control of the culture temperature, it was possible to get industrially interesting performance as regards glutamate concentration, yield and prod uctivity. A 24 h fermentation period enabled the production of 85 g/l of gl utamate in the production phase induced after a temperature shift from 33 d egrees C to 39 degrees C. The maximum specific production rate of glutamate was 0.63 g/g/h with a yield of 0.46 g of glutamate/gram of glucose. The tw o main co-products of the fermentation were lactate (11 g) and trehalose (1 2 g). Only trace amounts of other organic acids accumulated in the culture medium. This process offers an interesting alternative to currently employe d fermentation strategies in which biotin limitation and/or surfactant addi tion is used to induce glutamate production Simple control of fermenter coo ling can be used to control the onset of the production phase, offering sig nificant advantages from both an economic and a process robustness viewpoin t. (C) 1999 Elsevier Science Inc. All rights reserved.