Enhanced hypocrellin production of Shiraia sp. SUPER-H168 by overexpression of alpha-amylase gene

• Published in: PloS one Vol. 13; no. 5; p. e0196519
• Main Authors: Gao, Ruijie, Xu, Zhecun, Deng, Huaxiang, Guan, Zhengbing, Liao, Xiangru, Zhao, Ye, Zheng, Xiaohui, Cai, Yujie
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03-05-2018; Public Library of Science (PLoS)
• Subjects: Amylases; Amylopectin; Amylose; Ascomycota; Biofilms; Biology and Life Sciences; Biosynthesis; Biotechnology; Carbohydrates; Carbon; Carbon sources; Catabolism; Cornflour; Dehydrogenases; Fermentation; Funding; Fungi; Gene expression; Genes; Glucose; Glucosidase; Glycogen; Health aspects; Investigations; Laboratories; Life sciences; Maltose; Medicine and Health Sciences; Metabolism; Metabolites; Physical Sciences; Quinones; Research and Analysis Methods; Secondary metabolites; Starch; Sucrose; Sugar; α-Amylase; α-Glucosidase; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0196519

Relative expression levels of twenty-four amylase genes in Shiraia sp. SUPER-H168 were investigated by real-time quantitative PCR when various carbohydrates, including glucose, sucrose, maltose, amylose, amylopectin and corn flour, were used as carbon source. Genes, including an α-glucosidase gene Amy33 (2997 bp), an α-amylase gene Amy365-1 (1749 bp) and a glycogen debranching enzyme gene Amy130 (2487 bp), were overexpressed, and four overexpression transformants were constructed, respectively. When Amy365-1 and Amy130 were co-overexpressed, relative expression levels of seven hypocrellin biosynthesis genes and four related genes in central carbon catabolism were all increased. Expression of Amy33 was also increased along with increase of Amy365-1 and Amy130. Under liquid state fermentation, biomasses and hypocrellin productions were both gradually increased in four overexpression strains than those of wild type strain. Under SSF, hypocrellin production of Amy365-1 and Amy130 co-expression strain reached 71.85 mg/gds, which was 2.83 fold than that of wild type strain, and residual sugar was decreased from 35.47% to 16.68%. These results can provide a practical approach for other secondary metabolites by filamentous fungi under SSF when raw starch material is used as carbon source.