茉莉花香因其独特的芬芳深受人们喜爱。乙酸苄酯作为茉莉花香味的核心成分,在食品、化妆品和制药等行业具有广泛的应用。目前,乙酸苄酯的生产严重依赖化学合成。该研究在大肠杆菌中创建了乙酸苄酯的从头合成途径,通过微生物发酵实现以甘油为碳源合成乙酸苄酯。首先,该研究采用模块化方法,在BL21(DE3)中协同表达9种功能酶,构建了乙酸苄酯合成途径,获得菌株BZ04,通过两相发酵法实现从头合成(85.55±10.85) mg/L乙酸苄酯;然后,通过优化筛选不同来源的合成途径关键酶酰基转移酶,提高了乙酸苄酯产量。并在摇瓶发酵水平,优化了培养基中碳源、添加增溶剂以及增加O2的供应等发酵培养条件,进一步提高了乙酸苄酯产量。最后,在最佳发酵条件下,获得的工程菌株BZ05在摇瓶发酵水平,以甘油为简单碳源,合成了(592.22±36.95) mg/L的乙酸苄酯,相较于起始,乙酸苄酯产量提高了7倍。该研究实现了微生物发酵法从头合成乙酸苄酯,为乙酸苄酯的合成提供了一种绿色、可持续的生产方法。
The alluring aroma of jasmine is adored by people worldwide.Benzyl acetate, a key component of the scent of jasmine, is a valuable aromatic ester compound and extensively used as flavor and fragrance in food, cosmetics, and pharmaceutical industries.However, its current production heavily relies on chemical synthesis.In this study, a de novo synthesis pathway of benzyl acetate was established in Escherichia coli strains, and benzyl acetate was successfully synthesized by microbial fermentation.Firstly, to construct the synthesis pathway of benzyl acetate, nine functional enzymes were co-expressed in BL21 (DE3) using a modular strategy.The resulting strain BZ04 produced (85.55±10.85) mg/L benzyl acetate by two-phase in situ extractive fermentation.Subsequently, the production of benzyl acetate was enhanced through the optimal screening of key acyltransferase derived from various sources and optimization of various flask culture conditions including the screen of carbon sources, the addition of solubilizer, and the increase of oxygen supply.Under optimal fermentation conditions, the final strain of BZ05 produced (592.22±36.95) mg/L benzyl acetate from glycerol in shake flasks, which was seven times compared to original production of benzyl acetate.This study provides an eco-friendly and sustainable approach for benzyl acetate production.
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