We have engineered brewer's yeast as a general platform for de novo synthesis of diverse β-lactam nuclei starting from simple sugars, thereby enabling ready access to a number of structurally different antibiotics of significant pharmaceutical importance. The biosynthesis of β-lactam nuclei has received much attention in recent years, while rational engineering of non-native antibiotics-producing microbes to produce β-lactam nuclei remains challenging. Benefited by the integration of heterologous biosynthetic pathways and rationally designed enzymes that catalyze hydrolysis and ring expansion reactions, we succeeded in constructing synthetic yeast cell factories which produce antibiotic cephalosporin C (CPC, 170.1 ± 4.9 μg/g DCW) and the downstream β-lactam nuclei, including 6-amino penicillanic acid (6-APA, 5.3 ± 0.2 mg/g DCW), 7-amino cephalosporanic acid (7-ACA, 6.2 ± 1.1 μg/g DCW) as well as 7-amino desacetoxy cephalosporanic acid (7-ADCA, 1.7 ± 0.1 mg/g DCW). This work established a Saccharomyces cerevisiae platform capable of synthesizing multiple β-lactam nuclei by combining natural and artificial enzymes, which serves as a metabolic tool to produce valuable β-lactam intermediates and new antibiotics.

我们将啤酒酵母设计为从头开始的通用平台从单糖开始合成不同的β-内酰胺核，从而能够容易地获得许多具有重要药学意义的结构不同的抗生素。近年来，β-内酰胺核的生物合成备受关注，而合理设计非天然抗生素产生微生物以产生β-内酰胺核仍然具有挑战性。得益于异源生物合成途径的整合和合理设计的催化水解和扩环反应的酶，我们成功构建了生产抗生素头孢菌素C（CPC，170.1±4.9 μg/g DCW）和下游β-内酰胺的合成酵母细胞工厂。核，包括 6-氨基青霉酸 (6-APA, 5.3 ± 0.2 mg/g DCW)、7-氨基头孢菌酸 (7-ACA, 6.2 ± 1. 1 μg/g DCW）以及 7-氨基去乙酰氧基头孢菌素酸（7-ADCA，1.7 ± 0.1 mg/g DCW）。这项工作建立了一个Saccharomyces cerevisiae平台能够通过结合天然和人工酶合成多个β-内酰胺核，作为代谢工具生产有价值的β-内酰胺中间体和新型抗生素。