Temperature optimization for glycerol production by batch fermentation with Candida krusei

To maximize the final production yield and control the residual glucose at a low concentration during glycerol production by fermentation, optimal and sub-optimal temperature control strategies were investigated. The optimal control strategy of the culture temperature was determined precisely by Pon tryagin's Maximum Principle. By dividing the fermentation into multiple equ al subintervals and optimizing the constant temperatures of all subinterval s by a general static constrained global optimization approach, a sub-optim al control strategy could be obtained, which was more convenient to perform in practical fermentation, whilst a similar temperature profile and final glycerol yield to those of the optimal control strategy. The experimental a nd simulated results showed that, compared with those at the conventional t emperature of 35 degreesC, the final glycerol yield at the sub-optimal temp erature profile could be increased by 12-14% while the residual glucose was controlled at a value close to or less than 1% (w/v). (C) 2001 Society of Chemical Industry.