Vanillin production by Corynebacterium glutamicum using heterologous aromatic carboxylic acid reductases

作者：Miku Matsuzawa, Junko Itô, Keiko Danjo, Keita Fukui · 发表于：Biotechnology for Biofuels and Bioproducts · 年份：2024 · DOI：10.1186/s13068-024-02507-3 · 被引用次数：9 · 研究领域：Biochemical and biochemical processes、Microbial Metabolic Engineering and Bioproduction、Microbial metabolism and enzyme function

BACKGROUND: Vanillin is a flavoring substance derived from vanilla. We are currently developing a biotransformation method for vanillin production using glucose. This report describes the last step in vanillin production: the conversion of vanillic acid to vanillin. First, we selected Corynebacterium glutamicum as the host owing to its high vanillin resistance. The aromatic aldehyde reductase gene (NCgl0324) and vanillic acid demethylase protein subunits A and B gene (vanAB, NCgl2300-NCgl2301) were deleted in C. glutamicum genome to avoid vanillin degradation. Next, we searched for an aromatic carboxylic acid reductase (ACAR), which converts vanillic acid to vanillin. Seventeen ACAR homologs from various organisms were introduced into C. glutamicum. RESULTS: In vivo conversion experiments showed that eight ACARs were successfully expressed and produced vanillin. In terms of conversion activity and substrate specificity, the ACARs from Gordonia effusa, Coccomyxa subellipsoidea, and Novosphingobium malaysiense are promising candidates for commercial production. CONCLUSIONS: Corynebacterium glutamicum harboring Gordonia effusa ACAR produced 22 g/L vanillin, which is, to the best of our knowledge, the highest accumulation reported in the literature. At the same time, we discovered ACAR from Novosphingobium malaysiense and Coccomyxa subellipsoidea C-169 with high substrate specificity. These findings are useful for reducing the byproducts.