Optimization of lignin peroxidase production and stability by Phanerochaete chrysosporium using sewage-treatment-plant sludge as substrate in a stirred-tank bioreactor

J Ind Microbiol Biotechnol. 2009 May;36(5):757-64. doi: 10.1007/s10295-009-0548-5. Epub 2009 Mar 4.

Abstract

A laboratory-scale study was carried out to produce lignin peroxidase (ligninase) by white rot fungus (Phanerochaete chrysosporium) using sewage-treatment-plant (STP) sludge as the major substrate. The optimization was done using full-factorial design (FFD) with agitation and aeration as the two parameters. Nine experiments indicated by the FFD were fermented in a stirred-tank bioreactor for 3 days. A second-order quadratic model was developed using the regression analysis of the experimental results with the linear, quadratic, and interaction effects of the parameters. Analysis of variance (ANOVA) showed a high coefficient of determination (R (2)) value of 0.972, thus indicating a satisfactory fit of the quadratic model with the experimental data. Using statistical analysis, the optimum aeration and agitation rates were determined to be 2.0 vvm and 200 rpm, respectively, with a maximum activity of 225 U l(-1) in the first 3 days of fermentation. The validation experiment showed the maximum activity of lignin peroxidase was 744 U l(-1) after 5 days of fermentation. The results for the tests of the stability of lignin peroxidase showed that the activity was more than 80% of the maximum for the first 12 h of incubation at an optimum pH of 5 and temperature of 55 degrees C.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bioreactors / microbiology*
  • Culture Techniques / methods*
  • Enzyme Stability
  • Kinetics
  • Peroxidases / chemistry*
  • Peroxidases / metabolism*
  • Phanerochaete / chemistry
  • Phanerochaete / enzymology*
  • Phanerochaete / metabolism
  • Sewage / microbiology*
  • Waste Disposal, Fluid / methods*

Substances

  • Sewage
  • Peroxidases
  • lignin peroxidase