Elimination of by-product formation during production of 1,3-propanediol in Klebsiella pneumoniae by inactivation of glycerol oxidative pathway

• Published in: Applied microbiology and biotechnology 2009-09, Vol.84 (3), p.527-534
• Main Authors: Seo, Mi-Young, Seo, Jeong-Woo, Heo, Sun-Yeon, Baek, Jin-Oh, Rairakhwada, Dina, Oh, Baek-Rock, Seo, Pil-Soo, Choi, Min Ho, Kim, Chul Ho
• Format: Article
• Language: English
• Subjects: Amino acids; Applied Genetics and Molecular Biotechnology; Biodiesel fuels; Biotechnology; Biotechnology - methods; By products; Byproducts; Chemical products; Dehydrogenases; Deoxyribonucleic acid; DNA; E coli; Gene Deletion; Gene expression; Gene Expression Regulation, Bacterial; Genes; Genetic Engineering; Glycerol; Glycerol - metabolism; Inactivation; Kinases; Klebsiella pneumoniae; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - growth & development; Klebsiella pneumoniae - metabolism; Life Sciences; Metabolism; Metabolites; Microbial Genetics and Genomics; Microbiology; Mutants; Mutation; Oxidation; Oxidation-Reduction; Phosphotransferases (Alcohol Group Acceptor) - genetics; Phosphotransferases (Alcohol Group Acceptor) - metabolism; Plasmids; Propylene Glycols - metabolism; Studies; Sugar Alcohol Dehydrogenases - genetics; Sugar Alcohol Dehydrogenases - metabolism; Textile fibers
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-009-1980-1

The microbial production of 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae involves the formation of various by-products, which are synthesized through the oxidative pathway. To eliminate the by-products synthesis, the oxidative branch of glycerol metabolism was inactivated by constructing two mutant strains. In one of the mutant strains, the structural genes encoding glycerol dehydrogenase and dihydroxyacetone kinase were deleted from the chromosomal DNA, whereas in the second mutant strain dhaR, which is a putative transcription factor that activates, gene expression was deleted from the chromosomal DNA. In the resultant mutant strains lacking the dhaT gene encoding 1,3-PD oxidoreductase, which was simultaneously deleted while replacing the native promoter with the lacZ promoter, the by-product formation except for acetate was eliminated, but it still produced 1,3-PD at a lower level, which might be due to a putative oxidoreductase that catalyzes the production of 1,3-PD. The recombinant strains in which the reductive pathway was recovered produced slightly lower amount of 1,3-PD as compared to the parent strain, which might be due to the reduced activity of DhaB caused by the substitution of the promoter. However, the production yield was higher in the recombinant strain (0.57 mol mol⁻¹) than the wild type Cu strain (0.47 mol mol⁻¹).