Lactic acid production by Lactobacillus delbrueckii in a dual reactor system using packed bed biofilm reactor

Abstract

Aims: An integrated dual reactor system for continuous production of lactic acid by Lactobacillus delbrueckii using biofilms developed on reticulated polyurethane foam (PUF) is demonstrated.

Methods and results: Lactobacillus delbrueckii was immobilized on PUF, packed in a bioreactor and used in lactic acid fermentation. The rate of lactic acid production was significantly high with a volumetric productivity of 5 g l(-1) h(-1) over extended period of time. When coupled to a bioreactor, the system could be operated as dual reactor for over 1000 h continuously without augmentation of inoculum and no compromise on productivity.

Conclusions: Polyurethane foams offer an excellent support for biofilm formation.

Significance and impact of the study: The system was very robust and could be operated for prolonged period at a volumetric productivity of 4-6 g l(-1) h(-1).