Iterative gene circuit based on vibrio fischeri quorum sensing system and T7 expression system, and application of iterative gene circuit

Abstract

The invention discloses an iterative gene circuit based on a vibrio fischeri quorum sensing system and a T7 expression system. The iterative gene circuit comprises a signal molecular protein gene luxIof vibrio fischeri, a receptor protein gene luxR, a promoter sequence PluxI(1) for sensing a signal molecular and receptor protein complex, a T7 RNA polymerase gene T7 RNApoly and a green fluorescentprotein egfp for representing the circuit intensity. The gene circuit does not rely on an inducer and can utilize the T7 expression system to spontaneously and forcefully initiate target gene expression in any host bacterium; and gene elements are constructed on different expression vectors, the iterative gene circuit is constructed in engineering bacteria, the T7 expression system is utilized toamplify signals of the vibrio fischeri quorum sensing system, and the iterative gene circuit has the function of utilizing the T7 expression system to spontaneously and forcefully initiate target gene expression, and has a lower leakage ratio and higher initiating strength.

Description

technical field [0001] The invention belongs to the field of genetic engineering, and in particular relates to an iterative gene circuit based on a Vibrio fischeri quorum sensing system and a T7 expression system and an application thereof. Background technique [0002] Fermentation engineering bacteria need to synthesize a large amount of recombinant protein and build a synthetic pathway. If a large amount of recombinant protein is expressed at the starting point of culture, it will compete with cell metabolism for intracellular resources, which will bring a huge burden to the bacteria. The imbalance of metabolic network will lead to some toxic intermediates. The accumulation of products will also cause toxicity to the growth of the bacteria, making the strain unable to maintain a good growth state and affecting the yield of the final product. Therefore, the predecessors have explored a variety of operating elements to achieve the induction and regulation of genes, includin...

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Problems solved by technology

[0007] In the current technology, there are reports about the luxI / luxR quorum sensing system of Vibrio fischeri, which are generally used for research on quorum sensing inhibitors, by inhibiting signal molecules Synthesis of signal molecules, promoting the degradation of signal molecules and inhibiting the combination of signal molecules and receptor proteins and other means to inhibit the quorum sensing of microorganisms, prevent and treat pathogen infection and food spoilage caused by quorum sensing, but the use of Vibrio fischeri quorum sensing system for synthetic biological The gene circuit application of scientific design and signal regulation has not been reported yet, because the quorum sensing system of Vibrio fischeri itself has a certain expression leakage, which cannot achieve strict regulation of target genes; and the quorum sensing system of Vibrio fischeri The start-up strength is weak and cannot meet the downstream complex circuit requirements, which limits the application of quorum sensing systems

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