Temperature shift and feeding strategies for improving l-lactic acid production by Lactiplantibacillus plantarum in batch and fed-batch cultures. (February 2022)

• Record Type: Journal Article
• Authors: Sriphochanart, W.; Skolpap, W.
• Is Part Of: Process biochemistry. Volume 113(2022)
• Page Start: 11
• Page End: 21
• Publication Date: 2022-02
• Subjects: Temperature shift -- Feeding strategies -- l-lactic acid -- Lactiplantibacillus plantarum -- Fed-batch culture; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2021.12.006
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: Temperature shift from lower temperature in an early stage improves LAC formation. The highest P LAC is obtained in 25–35 °C shifted at the early exponential growth (3 h). P LAC is enhanced by feeding 20 g/L glucose at 9 h using exponent of 0.025 for feed rate. The combined temperature shift and off-line feeding strategy improves P LAC . Abstract: The optimal culture conditions for l -lactic acid production by Lactiplantibacillus plantarum TBRC 9667 were investigated. The suboptimal initial pH and initial temperature (for upshift to 30 °C after 5 h) were first determined in shake-flask cultures to be pH 5.5 and 25 °C, respectively. The three process variables analysis (initial temperature of 25 °C or 30 °C, temperature upshift to 30 °C or 35 °C, and temperature shift point at 3 or 5 h) revealed a 25 °C – 35 °C temperature shift after 3 h to be the most suitable conditions for l -lactic acid production in batch cultures at controlled pH 5.5. Fed-batch experiments were further conducted in 2-L bioreactors using different glucose concentrations (20 and 40 g/L) and feed rates (calculated with a feed-rate equation based on an off-line Markov chain algorithm), with an initial feed rate of 0.3 L/h. A 25 °C – 35 °C temperature shift after 3 h, with 20 g/L glucose feeding after 9 h using an exponent of 0.025 for feed-rate, gave a 1.5-fold improvement over the suboptimal batch culture. The results highlight the potential of integrated temperature shift and off-line feeding strategies for improving l -lactic acid production.