African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

Effect of medium pH on laccase zymogram patterns produced by Pleurotus ostreatus in submerged fermentation

Rubén Díaz1, Carmen Sánchez1, Martha D. Bibbins-Martínez2 and Gerardo Díaz-Godínez1,*
1Laboratory of Biotechnology, Research Centre for Biological Sciences, Universidad Autónoma de Tlaxcala, Tlaxcala CP 90062, Mexico. 2Centro de Investigación en Biotecnología Aplicada-IPN, Tlaxcala, México.
Email: [email protected]

  •  Accepted: 30 July 2011
  •  Published: 16 September 2011

Abstract

The number of laccase isoenzymes and laccase activities of Pleurotus ostreatus in buffered and non-buffered media were determined. In both culture media, the initial pH was adjusted to 3.5. Similar laccases activity (100-500 U/L) was observed in the range of 100-400 h (approximately) of fermentation in both media. Buffered culture medium yielded higher laccases activities (3200 U/L) at 500 h of fermentation than those observed in non-buffered culture medium (450 U/L). One laccase isoenzyme was produced during the entire fermentation process in both media. In the non-buffered medium, an additional isoenzyme of lower molecular weight than that produced in the entire fermentation process was produced at the beginning of the exponential phase of growth when the pH reached a value of 6.5. These results suggest that the fungus produces metabolites that modify the pH of the medium and that some laccases isoenzymes are regulated by pH signals. This is the first report on zymogram patterns from laccases activity of P. ostreatus at low pH.

 

Key words: Laccases, fermentation, Pleurotus ostreatus, zymogram.