Production of Rebaudioside A from Stevioside Catalyzed by the Engineered Saccharomyces cerevisiae

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• 作者：Yan Li ; Yangyang Li ; Yu Wang ; Liangliang Chen…
• 刊名：Applied Biochemistry and Biotechnology
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：178
• 期：8
• 页码：1586-1598
• 全文大小：578 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Biotechnology
  Biochemistry
  
• 出版者：Humana Press Inc.
• ISSN：1559-0291
• 卷排序：178

文摘

Rebaudioside A has superior taste quality among the steviol glycosides extracted from Stevia rebaudiana leaves. Given its high purity as a general-purpose sweetener, rebaudioside A has received significant attention and has been widely applied in food and beverages in recent decades. Stevioside is one of the major steviol glycosides and can be converted to rebaudioside A by the uridine-diphosphate dependent glucosyltransferase UGT76G1 in S. rebaudiana. To explore the applicability of and limits in producing rebaudioside A from stevioside through whole-cell biocatalysis, the engineered Saccharomyces cerevisiae expressing UGT76G1, using a newly constructed constitutive expression vector, was used as the whole-cell biocatalyst. Citrate was added to the reaction mixture to allow metabolic regulation when glucose was fed to provide the activated sugar donor UDP-glucose for glycosylation of stevioside in vivo. In an evaluation of the whole-cell reaction parameters involving cell permeability, temperature, pH, citrate and Mg2+ concentrations, and glucose feeding, production of 1160.5 mg/L rebaudioside A from 2 g/L stevioside was achieved after 48 h without supplementation of extracellular UDP-glucose.KeywordsRebaudioside ASaccharomyces cerevisiaeSteviosideUDP-glucosyltransferaseWhole-cell biocatalyst