The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
FEMS Microbiol Lett. 2022 Jul 13;369(1). doi: 10.1093/femsle/fnac056.
Substrate uptake and product export are important for microbial growth and product synthesis. Here, the glycerol uptake facilitator (GlpF) and the members of the resistance-nodulation-cell division (RND) type efflux system were overexpressed in Klebsiella pneumoniae to promote 1,3-propanediol (1,3-PDO) production. Overexpression of the endogenous K. pneumoniae GlpF improved glycerol dehydratase (GDHt) activity and promoted 1,3-PDO titer from 55.6 to 65.1 g/l. RND members AcrA and the AcrE had no impact on 1,3-PDO production. RND members AcrF and the TolC increased 1,3-PDO titer from 55.6 to 68.4 g/l and 65.4 g/l, respectively. MexB significantly decreased GDHt activity and 1,3-PDO titer. Notably, MexF dramatically enhanced GDHt activity and promoted 1,3-PDO titer and glycerol conversion rate to 74.0 g/l and 0.62 mol/mol, respectively. However, coexpression of the endogenous GlpF and MexF did not further improve 1,3-PDO production. The results present here provided novel information about the applications of the uptake of glycerol and the efflux of 1,3-PDO.
底物摄取和产物输出对微生物的生长和产物合成很重要。在这里，我们过表达了克雷伯氏肺炎菌中的甘油摄取促进剂（GlpF）和抗性调节细胞分裂（RND）型外排系统的成员，以促进 1,3-丙二醇（1,3-PDO）的生产。内源性克雷伯氏肺炎菌 GlpF 的过表达提高了甘油脱水酶（GDHt）的活性，并将 1,3-PDO 产量从 55.6 提高到 65.1 g/L。RND 成员 AcrA 和 AcrE 对 1,3-PDO 生产没有影响。RND 成员 AcrF 和 TolC 将 1,3-PDO 产量分别提高到 68.4 g/L 和 65.4 g/L。MexB 显著降低了 GDHt 的活性和 1,3-PDO 的产量。值得注意的是，MexF 极大地提高了 GDHt 的活性，并将 1,3-PDO 的产量和甘油转化率分别提高到 74.0 g/L 和 0.62 mol/mol。然而，内源性 GlpF 和 MexF 的共表达并没有进一步提高 1,3-PDO 的产量。本研究结果为甘油摄取和 1,3-PDO 外排的应用提供了新的信息。
