期刊
METABOLIC ENGINEERING
卷 70, 期 -, 页码 55-66出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.ymben.2022.01.008
关键词
Chitin oligosaccharides; Bacillus subtilis; UDP-GlcNAc; Metabolic engineering; Synthetic biology
资金
- National Natural Science Foundation of China [32021005, 31930085]
- Key Research and Development Program of China [2018YFA0900300, 2018YFA0900504]
- Fundamental Research Funds for the Central Universities [JUSRP52019A]
- Shandong Province Key R&D Program (Major Science and Technology Innovation Project) Project [2019JZZY011002]
This study demonstrated the de novo production of structurally defined chitooligosaccharides using combinatorial pathway engineering in Bacillus subtilis. By manipulating exogenous COSs synthase candidates and engineering UDP-GlcNAc pathways, the biosynthesis of COSs was significantly promoted, resulting in the highest reported titer of CTOSs. This research provides a feasible approach for commercial production of structurally defined chitooligosaccharides.
Chitooligosaccharides (COSs) have a widespread range of biological functions and an incredible potential for various pharmaceutical and agricultural applications. Although several physical, chemical, and biological techniques have been reported for COSs production, it is still a challenge to obtain structurally defined COSs with defined polymerization (DP) and acetylation patterns, which hampers the specific characterization and appli-cation of COSs. Herein, we achieved the de novo production of structurally defined COSs using combinatorial pathway engineering in Bacillus subtilis. Specifically, the COSs synthase NodC from Azorhizobium caulinodans was overexpressed in B. subtilis, leading to 30 +/- 0.86 mg/L of chitin oligosaccharides (CTOSs), the homo-oligomers of N-acetylglucosamine (GlcNAc) with a well-defined DP lower than 6. Then introduction of a GlcNAc synthesis module to promote the supply of the sugar acceptor GlcNAc, reduced CTOSs production, which suggested that the activity of COSs synthase NodC and the supply of sugar donor UDP-GlcNAc may be the limiting steps for CTOSs synthesis. Therefore, 6 exogenous COSs synthase candidates were examined, and the nodCM from Mesorhizobium loti yielded the highest CTOSs titer of 560 +/- 16 mg/L. Finally, both the de novo pathway and the salvage pathway of UDP-GlcNAc were engineered to further promote the biosynthesis of CTOSs. The titer of CTOSs in 3-L fed-batch bioreactor reached 4.82 +/- 0.11 g/L (85.6% CTOS5, 7.5% CTOS4, 5.3% CTOS3 and 1.6% CTOS2), which was the highest ever reported. This is the first report proving the feasibility of the de novo production of structurally defined CTOSs by synthetic biology, and provides a good starting point for further engineering to achieve the commercial production.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据