Extractive fermentation of l-(+)-lactic acid by Pediococcus pentosaceus using electrodeionization (EDI) technique

Abstract In this work, extractive fermentation of l -(+)-lactic acid (lactate) was carried out using an electrodeionization (EDI) technique. Pediococcus pentosaceus was used as the biocatalyst because of its homo-fermentative characteristic. The effect of initial lactate concentrations on microbial growth was initially investigated. A mathematical simulation of the product inhibition was successfully illustrated. It was found that the critical lactate concentration was approximately 80 g/L. Various operating conditions were investigated to assess the EDI performance. The system was subsequently applied for in situ removal of lactate from the fermentation broth. The specific deactivation constant ( k d ) was substantially reduced from 0.026 h −1 to 0.0054 h −1 resulting in a much improved half life of the biocatalyst. The highest lactate concentration in the receiving solution was 185 g/L.