Characterization of an extracellular laccase of Leptosphaerulina chartarum

World J Microbiol Biotechnol. 2014 Sep;30(9):2449-58. doi: 10.1007/s11274-014-1670-8. Epub 2014 May 21.

Abstract

Laccase-producing fungi were isolated from air, using selective media with a chromogenic substrate to indicate enzyme activity. The best laccase producer strain proved to be a Leptosphaerulina chartarum isolate. Laccase production was investigated in the presence of various inducers in different cultivation conditions. The extracellular laccase was purified for further investigations. SDS-PAGE showed that this laccase is a monomeric protein of 38 kDa molecular weight. The enzyme is active in the pH-range of 3.5-6, with an optimum at pH 3.8. It is active in the 10-60 °C temperature range, with an optimum at 40 °C. After 20 min incubation at temperatures above 70 °C the enzyme lost its activity. Degradation of seven aniline and phenol compounds (2,4-dichlorophenol; 2-methyl-4-chlorophenol; 3-chloroaniline; 4-chloroaniline; 2,6-dimethylaniline; 3,4-dichloroaniline and 3-chloro-4-methylaniline) was investigated, with or without guaiacol (2-methoxyphenol) as mediator molecule. Addition of a mediator to the system significantly increased the degradation levels. These results confirmed that the isolated laccase is able to convert these harmful xenobiotics at in vitro conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Microbiology
  • Aniline Compounds / metabolism
  • Ascomycota / enzymology*
  • Ascomycota / growth & development
  • Ascomycota / isolation & purification
  • Biotransformation
  • Culture Media / chemistry
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Stability
  • Hydrogen-Ion Concentration
  • Laccase / chemistry
  • Laccase / isolation & purification
  • Laccase / metabolism*
  • Molecular Weight
  • Phenols / metabolism
  • Temperature

Substances

  • Aniline Compounds
  • Culture Media
  • Phenols
  • Laccase
  • aniline