Process Biochem.

This work describes the development of a novel integrated system for lactic acid production by Actinobacillus succinogenes. Fermentation and separation were integrated with the use of a microfiltration (MF) membrane, and lactic acid was recovered by resin adsorption following MF. The fermentation broth containing residual sugar and nutrients was then recycled back into the fermenter after lactic acid adsorption. This novel approach overcame the problem of product inhibition and extended the cell growth period from 41 h to 120 h. Production of lactic acid was improved by 23% to 183.4 g L-1. The overall yield and productivity for glucose were 0.97 g g(-1) and 1.53 g L-1 h(-1), respectively. These experimental results indicate that the integrated system could benefit continuous production of lactic acid at high levels. (C) 2014 Elsevier Ltd. All rights reserved.This work describes the development of a novel integrated system for lactic acid production by Actinobacillus succinogenes. Fermentation and separation were integrated with the use of a microfiltration (MF) membrane, and lactic acid was recovered by resin adsorption following MF. The fermentation broth containing residual sugar and nutrients was then recycled back into the fermenter after lactic acid adsorption. This novel approach overcame the problem of product inhibition and extended the cell growth period from 41 h to 120 h. Production of lactic acid was improved by 23% to 183.4 g L-1. The overall yield and productivity for glucose were 0.97 g g(-1) and 1.53 g L-1 h(-1), respectively. These experimental results indicate that the integrated system could benefit continuous production of lactic acid at high levels. (C) 2014 Elsevier Ltd. All rights reserved