Method for synthesizing 2'-FL in escherichia coli by utilizing microbial quorum sensing and application

Abstract

The invention provides application of microbial quorum sensing. The microbial quorum sensing is used for self-induction synthesis of 2'-fucosyllactose (2'-FL) in a genome integration mode. The invention also provides a method for carrying out self-induced expression of related proteins in a 2'-FL synthetic pathway by utilizing microbial population induction in escherichia coli and synthesizing the2'-FL. According to the method for synthesizing the 2'-FL, a self-induced gene pathway is constructed by utilizing a promoter and a structural gene corresponding to vibrio fischer quorum sensing; wherein the gene pathway is luxpL-RBS-luxI-TT-luxpL-RBS-luxR-TT-lux pR-RBS-X-TT, and the X is a CDS sequence of a gene to be expressed. According to the method provided by the invention, a microbial quorum sensing mode is integrated into a genome of the escherichia coli, and related genes in the 2'-FL synthetic pathway are expressed, so that the escherichia coli obtains a positive feedback mechanism,and in-vivo synthesis of the 2'-FL can be automatically started when the density reaches a certain threshold value.

Description

technical field [0001] The invention belongs to the field of genetic engineering, in particular to the synthesis of 2'-FL. Background technique [0002] 1. Quorum sensing [0003] The quorum sensing system is a system of stimuli and responses that correlates with group density. Many bacteria use quorum sensing to regulate gene expression according to their population size. [0004] The signaling molecules produced and secreted by bacteria through quorum sensing are often referred to as autoinducers. These bacteria also have a receptor that detects specific signaling molecules (elicitors). When the inducer attaches to the receptor, it causes the transcriptional machinery of certain genes to be activated, including those genes used to synthesize the inducer. Few bacteria are able to detect autosecreted inducers. Therefore, in order to activate the transcriptional machinery of a specific gene, cells must interact with signaling substances secreted by other cells. [0005]...

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Problems solved by technology

[0025] At present, the commonly used method is to use plasmid vectors to supplement and overexpress the above-mentioned related genes. Commonly used promoters with strong expression in prokaryotic organisms include T7lac, Ptac, etc., which use isopropyl-β-D-sulfur Induction of galactoside (IPTG), a toxic laboratory agent that can cause damage when inhaled, ingested, or absorbed through the skin

[0026] The shortcomings of the current method are as follows: expression through plasmid vectors is easy to cause loss of plasmids, and the expression level is not as stable as genome integration; the use of inducers such as IPTG has cytotoxicity and potential risks, and it is not easy to purify and remove

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