Xu Jun-Wei, Ji Sen-Lin, Li Huan-Jun, Zhou Jiang-Sheng, Duan Yan-Qing, Dang Li-Zhi, Mo Ming-He
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China,
Bioprocess Biosyst Eng. 2015 Feb;38(2):399-405. doi: 10.1007/s00449-014-1279-1. Epub 2014 Sep 14.
This study aimed to improve the production of polysaccharide by engineering the biosynthetic pathway in Ganoderma lucidum through the overexpression of α-phosphoglucomutase (PGM) gene. PGM is responsible for the linkage between sugar catabolism and sugar anabolism. The effects of PGM gene overexpression on intracellular polysaccharide (IPS) content, extracellular polysaccharide (EPS) production and transcription levels of three genes encoding the enzymes involved in polysaccharide biosynthesis, including PGM, UDP-glucose pyrophosphorylase (UGP), and β-1,3-glucan synthase (GLS), were investigated. The maximum IPS content and EPS production in G. lucidum overexpressing the PGM gene were 23.67 mg/100 mg dry weight and 1.76 g/L, respectively, which were higher by 40.5 and 44.3% than those of the wild-type strain. The transcription levels of PGM, UGP and GLS were upregulated by 4.77-, 1.51- and 1.53-fold, respectively, in the engineered strain, suggesting that increased polysaccharide biosynthesis may result from a higher expression of those genes.
本研究旨在通过过表达α-磷酸葡萄糖变位酶（PGM）基因来改造灵芝的生物合成途径，从而提高多糖产量。PGM负责糖分解代谢与糖合成代谢之间的联系。研究了PGM基因过表达对细胞内多糖（IPS）含量、细胞外多糖（EPS）产量以及参与多糖生物合成的三种酶（包括PGM、尿苷二磷酸葡萄糖焦磷酸化酶（UGP）和β-1,3-葡聚糖合酶（GLS））编码基因转录水平的影响。过表达PGM基因的灵芝中，IPS的最大含量和EPS的产量分别为23.67 mg/100 mg干重和1.76 g/L，比野生型菌株分别高出40.5%和44.3%。在工程菌株中，PGM、UGP和GLS的转录水平分别上调了4.77倍、1.51倍和1.53倍，这表明这些基因的高表达可能导致多糖生物合成增加。
