摘要
酪醇是一种天然存在于橄榄油、酒及绿茶中的酚类化合物。由于酪醇具有抗炎症和抗氧化的生理活性,因此广泛应用于医药、化工等工业领域。传统的酪醇生产方法是化学合成法,但是这些方法存在着工艺复杂、得率低和环境污染等问题。另外,植物中较低的酪醇含量也限制了酪醇的分离纯化工艺研究。因此微生物发酵法生产酪醇研究越来越受到重视。通过在大肠杆菌内异源表达酿酒酵母中的丙酮酸脱羧酶基因ARO10,成功构建了合成酪醇的重组大肠杆菌。通过敲除预苯酸脱水酶编码基因pheA和苯乙醛脱氢酶编码基因feaB,提高了酪醇的合成能力。在最适的培养条件下,过表达ARO10基因的重组菌利用10 g/L葡萄糖作为碳源,发酵48 h酪醇产量可达4.15 mmol/L。研究发现,发酵培养基中外源添加酪氨酸能够提高重组大肠杆菌的酪醇合成能力。同时,研究还发现在大肠杆菌细胞中存在能够催化酪氨酸合成酪醇的前体物质4-羟基苯丙酮酸的酶。为工业水平微生物发酵法合成酪醇提供了思路。
Tyrosol(2-(4-hydroxyphenyl)ethanol)is an attractive phenolic compound that is naturally found in several foods such as olive oil,wines and green tea.Tyrosol has widely used in pharmaceutical,chemical and other industrial fields because of its anti-inflammatory and antioxidant activities.Traditionally,tyrosol is often produced chemically in industrial scale,however complex process,low yield and environmental issues are hampers.On the other hand,it would be hard to purify tyrosol from olive oil at an industrial scale because of its low concentration,absence of effective separation methods.Therefore,biotechnological production of tyrosol has been paid more and more attention.In this study,the phenylpyruvate decarboxylase gene ARO10 was cloned from Saccharomyces cerevisiae and introduced into Escherichia coli to generate a recombinant tyrosol producer.Furthermore,the genes of pheA and feaB encoding prephenate dehydratase and the endogenous phenylacetaldehyde dehydrogenase respectively,were deleted sequentially to improve tyrosol synthesis.Under the optimal fermentation conditions,the recombinant strain overexpressing ARO10 gene produced 4.15 mmol/L tyrosol from 10 g/L glucose in 48 h.Moreover,it shows that adding tyrosine in M9Y medium could increase tyrosol titer.Meanwhile,it also shows that it had several enzymes that converted tyrosine into 4-hydroyvphenylpyruvate.In summary,we successfully engineered a novel metabolic pathway in E.coli capable of producing tyrosol and provided a strategy for microbial tyrosol production in an industrial-scale.
作者
薛宇翔
陈献忠
杨翠
沈微
樊游
XUE Yuxiang;CHEN Xianzhong;YANG Cui;SHEN Wei;FAN You(Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China;School of Biotechnology,Jiangnan University,Wuxi 214122,China)
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2019年第10期152-159,共8页
Journal of Food Science and Biotechnology
基金
中央高校基本科研业务费专项资金项目(JUSRP51611A)
关键词
酪醇
丙酮酸脱羧酶
大肠杆菌
基因敲除
tyrosol
pyruvate decarboxylase
Escherichia coli
gene knockout
