PQQ Production via pqq Gene Cluster Modification
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Solution Overview
Problem
Current methods do not effectively enhance the expression of the pqq gene cluster in bacteria belonging to the genus Hyphomicrobium and the additional pqqA gene(s) in Methylobacterium or Hyphomicrobium for the purpose of producing pyrroloquinoline quinine (PQQ).
Innovation Solution
Modifying bacteria to enhance the expression of the pqq gene cluster and pqqA-like genes by introducing specific DNA fragments, such as those from the pqqABC/DE operon from Methylobacterium extorquens or the pqqABCDE cluster from Hyphomicrobium denitrificans, and increasing the gene copy number through vectors to increase PQQ production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional cultivation methods are used with wild-type strains, then the production process is simple, but PQQ accumulation in the culture medium is low
Solution Approach 1:
The patent changes the genetic parameters of the bacteria by introducing modified pqq gene clusters and pqqA genes with enhanced expression capabilities. This includes using strong promoters (like PmxaF), optimizing ribosome binding sites, and increasing gene copy numbers through plasmid vectors to achieve higher PQQ accumulation without fundamentally changing the production system
Solution Approach 2:
The patent uses plasmid vectors to introduce multiple copies of the pqq gene cluster and pqqA genes into the bacterial host. The plasmids serve as replicating copies that maintain high gene dosage, thereby increasing the expression levels of PQQ biosynthesis genes and enhancing PQQ production in the culture medium
2Productivity
If gene expression is enhanced through modification, then PQQ production increases, but the difficulty of detecting and measuring gene expression increases
Solution Approach 1:
The patent incorporates selectable markers (antibiotic resistance genes) and reporter systems that provide feedback on successful genetic transformation and gene expression. This allows researchers to easily identify and select transformed strains and measure gene expression levels through phenotypic markers and standardized assays, reducing the difficulty of detection despite enhanced expression
Data Source
AI summary
The present invention provides a method for producing PQQ using a bacterium belonging to the genera Methylobacterium or Hyphomicrobium, which has been modified to enhance the expression of pqq gene cluster and/or gene(s) encoding a precursor for PQQ biosynthesis.