One-step production of functional branched oligoglucosides with coupled fermentation of Pichia pastoris GS115 and Sclerotium rolfsii WSH-G01

• Published in: Bioresource technology Vol. 335; p. 125286
• Main Authors: Gao, Minjie, Xu, Ying, Yang, Guoshuai, Jin, Shuxia, Hu, Xiuyu, Jiang, Yun, Zhu, Li, Li, Zhitao, Zhan, Xiaobei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2021
• Subjects: Coupled fermentation; Endo-β-1,3-glucanase; Oligoglucosides; Pichia pastoris; Scleroglucan; Oligoglucosides; Pichia pastoris; Coupled fermentation; Scleroglucan; Endo-β-1,3-glucanase
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.125286

[Display omitted] •Error-prone PCR technology was implemented for endo-β-1,3-glucanase expression.•The mutant enzyme exhibited high activity towards curdlan and scleroglucan.•A coupled fermentation system of P. pastoris and S. rolfsii was established.•Branched β-oligoglucosides were produced directly by the coupled fermentation. Endo-β-1,3-glucanase with high specific activity is a prerequisite for enzymatic preparation of valuable β-oligoglucosides. Heterologous expression in Pichia pastoris GS115 with error-prone PCR technology was implemented, and the mutant strain 7 N12 was obtained. The mutant endo-β-1,3-glucanase showed efficient specific activities for degrading curdlan (366 U mg−1) and scleroglucan (274.5 U mg−1). Thereafter, one-step production of functional branched oligoglucosides was established with coupled fermentation of Pichia pastoris and Sclerotium rolfsii. During the fermentation process, the endo-β-1,3-glucanase secreted by Pichia pastoris GS115 can efficiently hydrolyse scleroglucan metabolized by Sclerotium rolfsii WSH-G01. The maximum yields of β-oligoglucosides in the shake flasks and 7-L bioreactor reached 1.73 g L−1 and 12.71 g L−1, respectively, with polymerization degrees of 2–17. The successful implementation of heterologous expression with error-prone PCR and the coupled fermentation simplified the multi-step enzymatic β-oligoglucoside preparation procedures, which makes it a potential strategy for industrial production of functional oligosaccharides.