Enhanced welan gum production using a two-stage agitation speed control strategy in Alcaligenes sp. CGMCC2428

Bioprocess Biosyst Eng. 2011 Jan;34(1):95-102. doi: 10.1007/s00449-010-0450-6. Epub 2010 Jul 17.

Abstract

Batch fermentative production of welan gum by Alcaligenes sp. CGMCC2428 was investigated under various oxygen supply conditions using regulating agitation speed. Based on a three kinetic parameters analysis that includes specific cell growth rate (μ), specific glucose consumption rate (q (s)), and specific welan formation rate (q (p)), a two-stage agitation speed control strategy was proposed to achieve high concentration, high yield, and high viscosity of welan. During the first 22 h, the agitation speed in 7.5 L fermenter was controlled at 800 rpm to maintain high μ for cell growth. The agitation was then reduced step-wise to 600 rpm to maintain a changing profile with stable dissolved oxygen levels and obtain high qp for high welan accumulation. Finally, the maximum concentration of welan was reached at 26.3 ± 0.89 g L(-1) with a yield of 0.53 ± 0.003 g g(-1) and the welan gum viscosity of 3.05 ± 0.10 Pa s, which increased by an average of 15.4, 15.2, and 20.1% over the best results controlled by constant agitation speeds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcaligenes / growth & development
  • Alcaligenes / metabolism*
  • Bioreactors
  • Culture Media
  • Fermentation
  • Glucose / metabolism
  • Industrial Microbiology / methods*
  • Kinetics
  • Oxygen / metabolism
  • Polysaccharides, Bacterial / analysis
  • Polysaccharides, Bacterial / biosynthesis*

Substances

  • Culture Media
  • Polysaccharides, Bacterial
  • welan
  • Glucose
  • Oxygen