Non-capsulated mutants of a chemical-producing Klebsiella pneumoniae strain
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To investigate the outcomes of capsule lost on cell transformation efficiency and chemicals (1,3-propanediol, 2,3-butanediol, and 2-ketogluconic acid) production by Klebsiella pneumoniae.
The cps gene cluster showed low sequence homology with pathogenic strains. The wza is a highly conserved gene in the cps cluster that encodes an outer membrane protein. A non-capsulated mutant was constructed by deletion of wza. Phenotype studies demonstrated that non-capsulated cells were less buoyant and easy to sediment. The transformation efficiency of the non-capsulated mutant reached 6.4 × 105 CFU μg−1 DNA, which is 10 times higher than that of the wild strain. 52.2 g 1,3-propanediol L−1, 30.7 g 2,3-butanediol L−1, and 175.9 g 2-ketogluconic acid L−1 were produced by non-capsulated mutants, which were 10–40% lower compared to wild strain. Furthermore, viscosities of the three fermentation broths decreased to approximately 1.3 cP from the range of 1.8–2.2 cP.
Non-capsulated K. pneumoniae mutants should allay concerns regarding biological safety, improve transformation efficiency, lower viscosity, and subsequently ameliorate the financial burden of the downstream process of chemicals production.
Keywords2,3-Butanediol Capsule 2-Ketogluconic acid Klebsiella pneumoniae 1,3-Propanediol
This work was supported by the National Natural Science Foundation of China (Grant Nos. 21576279, 20906076).
- Dean JA (1999) Lange's handbook of chemistry, 15th edn. McGraw-Hill, IncGoogle Scholar
- Fouts DE, Tyler HL, DeBoy RT, Daugherty S, Ren Q, Badger JH, Durkin AS, Huot H, Shrivastava S, Kothari S (2008) Complete genome sequence of the N2-fixing broad host range endophyte Klebsiella pneumoniae 342 and virulence predictions verified in mice. PLoS Genet 4:e1000141CrossRefPubMedPubMedCentralGoogle Scholar
- Rahn A, Drummelsmith J, Whitfield C (1999) Conserved organization in the cps gene clusters for expression of Escherichia coli group 1 K antigens: relationship to the colanic acid biosynthesis locus and the cps genes from Klebsiella pneumoniae. J Bacteriol 181:2307–2313PubMedPubMedCentralGoogle Scholar
- Rathnasingh C, Kim DK, Song H, Lee HJ, Do Seung, Park S (2012) Isolation and characterization of a new mucoid-free Klebsiella pneumoniae strain for 2,3-butanediol production. Afr J Biotechnol 11:11252–11261Google Scholar
- Struve C, Bojer M, Nielsen EM, Hansen DS, Krogfelt KA (2005) Investigation of the putative virulence gene magA in a worldwide collection of 495 Klebsiella isolates: magA is restricted to the gene cluster of Klebsiella pneumoniae capsule serotype K1. J Med Microbiol 54:1111–1113CrossRefPubMedGoogle Scholar