Microbial Biotechnology Research Center, Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeonbuk 56212, Republic of Korea.
Department of Food Science & Technology and Functional Food Research Center, Chonnam National University, Gwangju 61186, Republic of Korea.
Bioresour Technol. 2021 Oct;337:125361. doi: 10.1016/j.biortech.2021.125361. Epub 2021 Jun 2.
Organic acids produced during the fermentation of lactic acid bacteria inhibit cellular growth and the production of 1,3-propanediol (1,3-PDO). Lactobacillus reuteri JH83, which has an increase of 18.6% in organic acid resistance, was obtained through electron beam irradiation mutagenesis irrelevant to the problem of genetically modified organisms. The maximum bioconversion of 1,3-PDO in fed-batch fermentation using pure glycerol by L. reuteri JH83 was 93.2 g/L at 72 h, and the productivity was 1.29 g/L·h, which achieved an increase by 34.6%, compared to that of the wild-type strain. In addition, the result of fed-batch fermentation for the production of 1,3-PDO using crude glycerol was not significantly different from that of pure glycerol. Additionally, transcriptome analysis confirmed changes in the expression levels of sucrose phosphorylase, which is a major facilitator superfamily transporter, and muramyl ligase family proteins, which protect lactic acid bacteria from various stressors, such as organic acids.
在乳酸菌发酵过程中产生的有机酸会抑制细胞生长和 1,3-丙二醇（1,3-PDO）的生产。通过与转基因生物问题无关的电子束辐照诱变，获得了有机酸抗性提高 18.6%的罗伊氏乳杆菌 JH83。使用纯甘油进行补料分批发酵时，罗伊氏乳杆菌 JH83 的 1,3-PDO 的最大生物转化为 72 h 时的 93.2 g/L，产率为 1.29 g/L·h，与野生型菌株相比提高了 34.6%。此外，使用粗甘油进行 1,3-PDO 生产的补料分批发酵的结果与使用纯甘油的结果没有显著差异。此外，转录组分析证实了蔗糖磷酸化酶和 muramyl 连接酶家族蛋白的表达水平发生了变化，蔗糖磷酸化酶是主要易化超级家族转运蛋白，muramyl 连接酶家族蛋白可以保护乳酸菌免受各种应激源的影响，如有机酸。
