Abstract

Currently, some cases about the expression of flavor peptides with microorganisms were reported owing to the obvious advantages of biological expression over traditional methods. However, beefy meaty peptide (BMP), the focus of umami peptides, has neither been concerned in its safe expression nor its overproduction in fermenter. In this study, multi-copy BMP (8BMP) was successfully auto-inducibly expressed and efficiently produced in Bacillus subtilis 168. First, 8BMP was successfully auto-inducibly expressed with srfA promoter in B. subtilis 168. Further, the efficient production of 8BMP was researched in a 5-L fermenter: the fermentation optimized by Pontryagin’s maximum principle obtained the highest 8BMP yield (3.16 g/L), which was 1.2 times and 1.8 times than that of two-stage feeding cultivation (2.67 g/L) and constant-rate feeding cultivation (1.75 g/L), respectively. Overall, the auto-inducible expression of 8BMP in B. subtilis and fermentation with Pontryagin’s maximum principle are conductive for overproduction of BMP and other peptides.

中文翻译：

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枯草芽孢杆菌对牛肉肉肽的自诱导表达及高细胞密度发酵

摘要

目前，由于生物学表达相对于传统方法的明显优势，已经报道了一些用微生物表达风味肽的案例。然而，鲜味肽（BMP）是鲜味肽的重点，它的安全表达或在发酵罐中的过量生产都没有受到关注。在这项研究中，多拷贝BMP（8BMP）在枯草芽孢杆菌168中成功地自动诱导表达并有效产生。首先，srfA启动子在枯草芽孢杆菌中成功地自动诱导表达8BMP 。168.此外，还研究了在5升发酵罐中高效生产8BMP的方法：通过Pontryagin最大原理优化的发酵获得了最高的8BMP产量（3.16 g / L），是两阶段法的1.2倍和1.8倍饲料培养（2.67 g / L）和恒速饲料培养（1.75 g / L）。总体而言，在枯草芽孢杆菌中自动诱导表达8BMP以及采用Pontryagin的最大原理进行发酵对于BMP和其他肽的过量生产具有传导性。