Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea.
Biotechnol J. 2017 Nov;12(11). doi: 10.1002/biot.201700114. Epub 2017 Sep 15.
Dimethyl itaconate is an important raw material for copolymerization, but it is not synthesized from itaconic acid by organisms. Moreover, Corynebacterium glutamicum is used as an important industrial host for the production of organic acids, but it does not metabolize itaconic acid. Therefore, the biosynthetic route toward dimethyl itaconate from itaconic acid is highly needed. In this study, a biological procedure for dimethyl itaconate production is developed from rice wine waste-derived itaconic acid using the engineered C. glutamicum strain. The first step is to investigate the effect of the co-overexpression of the codon-optimized cis-aconitic acid decarboxylase (CadA*) and a transcriptional regulator of genes involved in acetic acid metabolism (RamA) on itaconic acid production. The second step is to convert itaconic acid into dimethyl itaconate by lipase-catalyzed esterification. The CadA* and RamA-overexpressing CG4 strain increases the itaconic acid concentration under N-starvation with glucose and acetic acid compared with the concentration produced in the base mCGXII medium with glucose. Furthermore, the rice wine waste-derived itaconic acid is successfully converted into dimethyl itaconate using lipase from Rhizomucor miehei and a methanol substrate. This study is the first trial for bio-based production of dimethyl itaconate from rice wine waste-derived itaconic acid.
衣康酸二甲酯是共聚的重要原料，但不能由生物体从衣康酸合成得到。而且，谷氨酸棒杆菌是生产有机酸的重要工业宿主，但不能代谢衣康酸。因此，需要从衣康酸生物合成衣康酸二甲酯的途径。在这项研究中，利用工程化的谷氨酸棒杆菌菌株，从米酒废水中的衣康酸出发，开发了一种生产衣康酸二甲酯的生物工艺。第一步是研究共表达经过密码子优化的顺乌头酸脱羧酶（CadA*）和参与乙酸代谢的基因的转录调节剂（RamA）对衣康酸生产的影响。第二步是通过脂肪酶催化酯化将衣康酸转化为衣康酸二甲酯。与在含有葡萄糖的基础 mCGXII 培养基中产生的浓度相比，CadA*和 RamA 过表达的 CG4 菌株在葡萄糖和乙酸的 N 饥饿条件下增加了衣康酸的浓度。此外，成功地使用米黑根毛霉的脂肪酶和甲醇底物将米酒废水中的衣康酸转化为衣康酸二甲酯。本研究首次尝试从米酒废水中的衣康酸生物合成生产衣康酸二甲酯。
