Abstract:

Laccase from a newly isolated wood-rot fungus Psathyrella Candolleana,was produced via the submerged fermentation,and high-purity laccase was obtained by means of the ammonium sulfate precipitation and the ion-exchange chromatography. Then,the enzymatic properties of the laccase were also analyzed. The results indicate that the maximal activity of the laccase from P. candolleana in the fermentor reaches 9100U/L,that the active
component of the laccase achieved after 13. 2-fold purification is of a specific activity of 438. 0U/mg with a yield of 50. 1%,that the molecular mass and Michaelis constant of the laccase are respectively about 61. 2ku and 16μmol /L,and that the optimal pH value and temperature for the laccase activity are 5. 0 and 45℃,respectively. Moreover,it is also found that the laccase activity is stable under 4 ~10℃ at pH 9. 0 and is not sensitive to Mg^{2 +} ,Mn^{2 +} and Zn^{2 +} .

Key words: Psathyrella Candolleana, white-rot fungus, laccase, purification, laccase activity, stability