A simple downstream processing protocol for the recovery of lactic acid from the fermentation broth

• Published in: Bioresource technology 2020-12, Vol.318, p.124260-124260, Article 124260
• Main Authors: Kumar, Sumit, Yadav, Neerja, Nain, Lata, Khare, Sunil Kumar
• Format: Article
• Language: English
• Subjects: Downstream process; Fermentation broth; Lactic acid; Lactic acid bacteria (LAB); Solvent extraction
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.124260

•A simple and economical process for downstream of lactic acid has been developed.•The pH of the extraction medium was critical during lactic acid purification.•Optimized downstream process conditions resulted in a yield of 86% and 93% purity.•The purified lactic acid was further characterized by FTIR and NMR. Lactic acid is one of the essential platform chemicals, and despite the availability of a range of downstream processes, its effective recovery is still elusive. A phase partitioning process using n-butanol and a chaotropic salt ammonium sulphate was developed to recover lactic acid from the fermentation broth of Lactobacillus pentosus SKL-18. During the optimization of various process parameters, the extraction medium's pH was found to be critical, with 2.5 being the best. The optimized process resulted in a lactic acid yield of 86% and found it to be 93% pure. The purity and characteristics of lactic acid were confirmed by FTIR and NMR spectra. This solvent-based extraction procedure is an economical and straightforward downstream process for purifying lactic acid produced from agro- and bakery-residues. The pure lactic acid can further be used for enzymatic synthesis of high value-added product PLA, a biodegradable and biocompatible plastics.