Control of cell and lactate concentration in a hollow-fiber bioreactor for lactic acid fermentation.

Abstract

Fromthe amount of alkaline solution supplied for neutralizing the broth, lactate concentration was estimated on line in the fermentation of Streptococcus cremoris. Cell concentration in the broth was also monitored on line using a turbidimeter. The monitoring system was applied to the culture accompanied by filtration, and both cell and lactate concentrations were controlled at constant levels by on-off control. In this culture, cells and lactate were continuously produced at constant rates, and the concentrations in the fermenter were kept constant.

The Role of Lactic Acid Adsorption by Ion Exchange Chromatography

“…With the development of the membrane process, electrodialysis fermentation is promising since it can remove the lactic acid from the broth and maintain the pH in a proper value. However, the approach also encounters many problems such as membrane fouling, deionization of the fermentation broth and a higher operating cost [4] .…”

Optimal Operation Derived by Green's Theorem for the Cell‐Recycle Filter Fermentation Focusing on the Efficient Use of the Medium

“…Noting that lactate is the only organic acid to be produced by homofermentative lactic acid bacteria, the lactic acid concentration in the broth can be estimated on-line from the amount of alkaline solution supplied to neutralize the culture broth, such as (Wang et al, 1988)…”

“…One idea was to keep the lactate concentration constant with feedback control (Wang et al, 1988;Shi et al, 1990). Although this method achieved some success, a more efficient strategy needs to be developed for efficient use of the medium in practice.…”

Adsorption Studies of Lactic Acid by Polymeric Adsorbent Amberlite XAD-7: Equilibrium and Kinetics

“…5 Several techniques can be used to decrease impurities in the end product including extraction, 6 membrane process, 7 electrodialysis, 8 reactive distillation 9 and ion-exchange. 10 In fact, lactic acid is scarcely extractable by conventional solvents because of its hydrophilic nature. Reactive extraction processes have been used as an alternative to the conventional method.…”