Co-production of Nisin and γ-Aminobutyric Acid by Engineered Lactococcus lactis for Potential Application in Food Preservation
Co-production of Nisin and γ-Aminobutyric Acid by Engineered Lactococcus lactis for Potential Application in Food Preservation
复制标题
工程乳酸乳球菌联合生产乳链菌肽和γ-氨基丁酸，在食品保鲜中的潜在应用
DOI：
10.3389/fmicb.2020.00049
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发表时间：
2020-01-29
影响因子：
5.2
通讯作者：
Qiao, Jianjun
中科院分区：
文献类型：
--
作者：
Liu, Jiaheng;Meng, Furong;Qiao, Jianjun
微生物污染和氧化损伤是维持食品质量和延长食品保质期的两大挑战。在这里，我们开发了一种乳酸乳球菌发酵系统，可以同时产生抗菌肽Nisin和抗氧化剂伽马氨基丁酸(GABA)。在该系统中，我们通过表达谷氨酸脱羧酶和谷氨酸/GABA逆向转运蛋白，对乳链菌素产生菌L.lactis F44进行了代谢工程，使其能够产生GABA。GABA的生物合成可以通过提高菌株的耐酸性来促进Nisin的生产。采用两段pH控制发酵策略，工程菌的GABA产量可达9.12g/L，是pH恒定发酵的2.2倍。此外，我们还展示了冻干发酵产品作为防腐剂在改善肉类和水果保鲜性能方面的潜在应用。这些结果表明，Nisin-GABA联合产生菌的发酵产物可以作为一种低成本、易制备、高性能的食品防腐剂。
Microbiological contamination and oxidative damage are the two main challenges in maintaining quality and improving shelf-life of foods. Here, we developed a Lactococcus lactis fermentation system that could simultaneously produce nisin, an antimicrobial peptide, and gamma-aminobutyric acid (GABA), an antioxidant agent. In this system, we metabolically engineered a nisin producing strain L. lactis F44 for GABA production by expression of glutamate decarboxylase and glutamate/GABA antiporter. GABA biosynthesis could facilitate nisin production through enhancing acid resistance of the strain. By applying a two-stage pH-control fermentation strategy, the engineered strain yielded up to 9.12 g/L GABA, which was 2.2 times higher than that of pH-constant fermentation. Furthermore, we demonstrated the potential application of the freeze-dried fermentation product as a preservative to improve the storage performance of meat and fruit. These results suggested that the fermentation product of nisin-GABA co-producing strain could serve as a cost-effective, easily prepared, and high-performance food preservative.