Isolation and characterization of a new mucoid-free Klebsiella pneumoniae strain for 2,3-butanediol production

  • Chelladurai Rathnasingh
  • Duk-Ki Kim
  • Hyohak Song
  • Hee Jong Lee
  • Doyoung Seung
  • Sunghoon Park
Keywords: 2, 3-Butanediol, Klebsiella pneumoniae, isolation, capsular polysaccharides, scanning electron microscopy

Abstract

The secretion of mucoid substances by Klebsiella pneumoniae, a natural 2,3-butanediol (2,3-BD) hyper-producer, hinders its application in large-scale fermentation because of pathogenicity, fermentation instability, and downstream difficulty. In this study, 14 K. pneumoniae strains were isolated from a waste water treatment plant and their 2,3-BD production efficiencies were assessed with the strain K. pneumoniae DSM2026. Among various strains isolated, K. pneumoniae GSC010 and GSC112 produced relatively large amounts of 2,3-BD compared to other isolates; and their 2,3-BD production was consistent with DSM2026. Meanwhile, mucoidic characteristics of GSC010 were more or less similar to DSM2026, which was observed by scanning electron microscope (SEM) as a characteristic intercalated thread anchored on the surface of the cells. However, no polysaccharide materials were found in a non-mucoid cell, GSC112. Fed-batch culture of GSC112 with continuous glucose feeding resulted in the production of 2,3-BD at 52.4 g/l with 2,3-BD yield and overall productivity of 0.27 g/g glucose and 0.52 g/l/h, respectively. These results strongly suggest that the newly isolated mucoid-free K. pneumoniae GSC112 has potential for industrial production of 2,3-BD.

Keywords: 2,3-Butanediol, Klebsiella pneumoniae, isolation, capsular polysaccharides, scanning electron microscopy

Published
2016-01-20
Section
Articles

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eISSN: 1684-5315