Dialysis continuous process for ammonium lactate fermentation: Simulated prefermentor and cell‐recycling systems

Abstract

SummaryA generalized mathematical model, previously developed and experimentally validated, was modified and used to computer-simulate the outcomes of adding two systems for increasing the concentration of cell mass in the fermentor, and thereby the rate and extent of substrate conversion, in a dialysis continuous process for the ammonium lactate fermentation of deproteinized whey. The addition of a nondialysis continuous prefermentor would not improve the process. However, the addition of cell recycling (feedback) would greatly improve the process: with total recycling the cell retention time would be reduced ninefold, and the extent of converting substrate to product would be increased 25% and accomplished almost entirely by maintenance metabolism.

Novel Method of Lactic Acid Production by Electrodialysis Fermentation

“…As the solubility of calcium lactate is low (3), at high concentrations of this substance the broth tends to solidify, complicating following procedures (3). Recently, there have been reports of a continuous dialysis process for ammonium lactate fermentation with neutralization to a constant pH achieved by NH40H (4,14,(21)(22)(23)(24) and lactic acid production in a hollow fiber fermentor with neutralization achieved by NaOH (19). In the former experiments, good results were obtained.…”

Theoretical Analysis of the Effect of Cell Recycling on Recombinant Cell Fermentation Processes

“…In 1970, Pirt and Kurowski reported an experimental and theoretical study for chemostat operation with a cell recycle. Many different cell recycle fermentor configurations have been proposed, and different ways of cell retention have been proposed (Cysewski and Wilke, 1977;Stieber and Gerhardt, 1981;Toda and Dunn, 1982;Hamer, 1982), including dialysis and microfiltration. Mathematical descriptions and an experimental study of the recycle fermentation for commercial products of bacterial origin were presented by Bull (1981).…”

Continuous culture of Streptococcus cremoris on lactose using various medium conditions

“…Their growth kinetics have been investigated under various environmental conditions and various g~owth models proposed, mainly taking into consideration the inhibitory effect of the end-product (Luedecking and Piret 1959;Hanson and Tsao 1972;Tsao and Hanson 1975;Rogers et al 1978;Jorgensen and Nikolajsen 1987). In addition, with a view to bioreactor developments, the performances of novel systems have been frequently compared to conventional continuous cultures (Friedman and Gaden 1970;Stieber and Gerhardt 1981;Stenroos et al 1982;Vick Roy et Offprint requests to: A. Pareilleux al. 1983;Boyaval et al 1987).…”