Application of CRISPRi gene inhibition system in construction of genetically engineered bacteria

The invention discloses an application of a CRISPRi (clustered regularly interspaced short palindromic repeats i) gene inhibition system in construction of genetically engineered bacteria. The CRISPRi gene inhibition system comprises a dCas9 expression box and an sgRNA expression box, wherein the dCas9 expression box and the sgRNA expression box are connected with each other; wherein the dCas9 expression cassette comprises a dCas9 gene and a promoter at the upstream of the dCas9 gene, and the sgRNA expression cassette comprises a nucleotide sequence for coding the sgRNA and a promoter at the upstream of the sgRNA, specifically as described in the text. The CRISPRi gene inhibition system flexibly regulates the expression effect of the pxa1 gene in Candida sp. Under the condition of not damaging the pxa1 gene sequence, regulates the metabolic pathway of the long-chain dicarboxylic acid in the Candida sp. On the premise of avoiding the defects caused by the traditional gene modification method, and screens to ob