A four-microorganism three-step fermentation process for producing medium-chain-length polyhydroxyalkanoate from starch

3 Biotech. 2020 Aug;10(8):352. doi: 10.1007/s13205-020-02347-6. Epub 2020 Jul 23.


In this study, a four-microorganism three-step fermentation process was established for producing medium-chain-length polyhydroxyalkanoate (mcl-PHA) from starch, which was used as the sole carbon source. The four microorganisms used for this process were Aspergillus niger, Saccharomyces cerevisiae L2612, Acetobacter orientalis, and Pseudomonas putida KT2440-acs. The initial carbon source starch concentration was set to 30 g/L, the maximum glucose concentration reached 17.66 g/L at 48 h after starch hydrolysis, and then, 2.36 g/L of acetic acid was obtained at 96 h. The final output of mcl-PHA was 0.5 g/L at 144 h, overall productivity for mcl-PHA was 3.47 mg/(L·h) and the total starch to mcl-PHA yield for the process was 16.67 mg/g. Although the overall yield and conversion rate of this process were not high, this is the first attempt to produce mcl-PHA using starch as a substrate, and it provides a feasible strategy for producing PHA from kitchen waste. The production process of mcl-PHA with a clear flora structure and short fermentation cycle was realized.

Keywords: Acetic acid; Medium-chain-length polyhydroxyalkanoate; Pseudomonas putida KT2440-acs; Starch.