Removal of pathogenic factors from 2,3-butanediol-producing Klebsiella species by inactivating virulence-related wabG gene

• Published in: Applied microbiology and biotechnology 2013-03, Vol.97 (5), p.1997-2007
• Main Authors: Jung, Sung-Geun, Jang, Jun-Ho, Kim, Ah-Young, Lim, Min-Cheol, Kim, Borim, Lee, Jinwon, Kim, Young-Rok
• Format: Article
• Language: English
• Subjects: Acetoin; Acetoin - metabolism; Analysis; Antigens; Applied Genetics and Molecular Biotechnology; Bacteria; Biomedical and Life Sciences; Biotechnology; Biotechnology - methods; Butylene Glycols - metabolism; Cell Line; Cell metabolism; Chemical synthesis; Epithelial Cells - microbiology; Gene Knockout Techniques; Gene Targeting; Genetic aspects; Genetic engineering; Humans; Klebsiella; Klebsiella oxytoca; Klebsiella oxytoca - genetics; Klebsiella oxytoca - growth & development; Klebsiella oxytoca - metabolism; Klebsiella oxytoca - pathogenicity; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - growth & development; Klebsiella pneumoniae - metabolism; Klebsiella pneumoniae - pathogenicity; Lactates - metabolism; Life Sciences; Lipopolysaccharides - biosynthesis; Metabolic Engineering - methods; Microbial Genetics and Genomics; Microbiology; Microorganisms; Mutation; Observations; Pathogens; Pharmaceutical sciences; Plasmids; Pneumonia; Recombination, Genetic; Studies; Virulence; Virulence (Microbiology); Virulence Factors - genetics
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-012-4284-9

Klebsiella species are the most extensively studied among a number of 2,3-butanediol (2,3-BDO)-producing microorganisms. The ability to metabolize a wide variety of substrates together with the ease of cultivation made this microorganisms particularly promising for the application in industrial-scale production of 2,3-BDO. However, the pathogenic characteristics of encapsulated Klebsiella species are considered to be an obstacle hindering their industrial applications. Here, we removed the virulence factors from three 2,3-BDO-producing strains, Klebsiella pneumoniae KCTC 2242, Klebsiella oxytoca KCTC1686, and K. oxytoca ATCC 43863 through site-specific recombination technique. We generated deletion mutation in wabG gene encoding glucosyltransferase which plays a key role in the synthesis of outer core lipopolysaccharides (LPS) by attaching the first outer core residue d -GalA p to the O-3 position of the l , d -Hep p II residue. The morphologies and adhesion properties against epithelial cells were investigated, and the results indicated that the wabG mutant strains were devoid of the outer core LPS and lost the ability to retain capsular structure. The time profile of growth and 2,3-BDO production from K. pneumoniae KCTC 2242 and K. pneumoniae KCTC 2242 ΔwabG were analyzed in batch culture with initial glucose concentration of 70 g/l. The growth was not affected by disrupting wabG gene, but the production of 2,3-BDO decreased from 31.27 to 22.44 g/l in mutant compared with that of parental strain. However, the productions of acetoin and lactate from wabG mutant strain were negligible, whereas that from parental strain reached to ~5 g/l.