Genetically modified violacein biosynthetic gene cluster, recombinant expression vector, engineering bacterium and application thereof

The invention discloses a genetically modified violacein biosynthetic gene cluster, a recombinant expression vector, engineering bacteria and application thereof. The ribosome binding site of the violacein biosynthetic gene cluster is subjected to site-specific mutagenesis and codon deletion mutation transformation, so that effective translation of violacein synthetic protein is promoted, and thetransformed gene cluster with remarkably improved production potential is obtained; by introducing the modified gene cluster or the recombinant vector containing the modified gene cluster into host bacteria, engineering bacteria for high yield of violacein are obtained; furthermore, fermentation conditions of engineering bacteria are optimized, and a method for separating and purifying violacein is provided. The genetic engineering strain constructed by the invention has the advantages that the yield of violacein can be obviously improved; different from conventional low-temperature fermentation of violacein at 20 DEG