School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai, 201418, China.
Shanghai International Travel Healthcare Center, Shanghai Customs District P. R, Shanghai, 200335, China.
Microb Cell Fact. 2021 Apr 9;20(1):83. doi: 10.1186/s12934-021-01570-x.
Poly-γ-glutamic acid (γ-PGA) and nattokinase (NK) are the main substances produced by Bacillus subtilis natto in solid-state fermentation and have wide application prospects. We found that our strains had higher activity of nattokinase when soybeans were used as substrate to increase the yield of γ-PGA. Commercial production of γ-PGA and nattokinase requires an understanding of the mechanism of co-production. Here, we obtained the maximum γ-PGA yield (358.5 g/kg, w/w) and highest activity of NK during fermentation and analyzed the transcriptome of Bacillus subtilis natto during co-production of γ-PGA and NK. By comparing changes in expression of genes encoding key enzymes and the metabolic pathways associated with the products in genetic engineering, the mechanism of co-production of γ-PGA and nattokinase can be summarized based on RNA-seq analysis. This study firstly provides new insights into the mechanism of co-production of γ-PGA and nattokinase by Bacillus subtilis natto and reveals potential molecular targets to promote the co-production of γ-PGA and nattokinase.
聚γ-谷氨酸（γ-PGA）和纳豆激酶（NK）是纳豆芽孢杆菌固态发酵生产的主要物质，具有广泛的应用前景。我们发现，以大豆为底物时，菌株产纳豆激酶的活力较高，从而提高了γ-PGA 的产量。γ-PGA 和纳豆激酶的商业化生产需要了解共生产的机制。在这里，我们在发酵过程中获得了最大的γ-PGA 产量（358.5 g/kg，w/w）和 NK 的最高活性，并分析了共生产γ-PGA 和 NK 时纳豆芽孢杆菌的转录组。通过比较基因工程中与产物相关的关键酶编码基因和代谢途径表达的变化，基于 RNA-seq 分析可以总结 γ-PGA 和纳豆激酶共生产的机制。本研究首次为纳豆芽孢杆菌共生产 γ-PGA 和纳豆激酶的机制提供了新的见解，并揭示了促进 γ-PGA 和纳豆激酶共生产的潜在分子靶点。
