The Effect of Calcium on Ligninolytic Enzymes Production by Pleurotus ostreatus During Vine Sawdust Fermentation

摘要

Edible and medicinal white-rot species, Pleurotus ostreatus (Jacq.: Fr.) Kumm., is distinguished by possession of a potent ligninolytic enzyme system, which participates in successful degradation of different aromatic compounds. Due to the ability of ligninolytic enzymes production, P. ostreatus takes important place in degradation of various raw plant materials that are produced in enormous amount worlwide. Vine sawdust is a common agricultural waste in some regions and is prospective substrate for the bioconversion into fungal biomass and ligninolytic enzymes. Regarding to the fact that some micro-and macroelements have influence on the growth and physiological processes in the fungi, the aim of this study was to evaluate if Ca added to the medium in form of CaCl2 ? 2H2O affect the activity of Mnoxidizing peroxidases and laccases, after seven and ten days of vine sawdust solid state fermentation. Comparing with the control, Ca showed inhibitory effect on Mn-oxidizing peroxidase activity on one side and highly stimulatory effect on laccase activity on the other. After seven days of cultivation, Lac activity was about 47% higher in medium with Ca (470. 26 U/L and 691. 70 U/L, respectively), while on tenth cultivation day slightly lower enhancement was measured (41%), 369 U/L in control and 520.49 U/L in medium with Ca. Decreasing in Lac activity, of about 20% was noticed with cultivation time, in both tested media. The level of Mn-oxidizing peroxidases activity significantly increased with cultivation time, especilally in medium with Ca. Based on these results, it could be concluded that the presence of Ca in medium can advance various biotechnological processes among which is biodegradation of agricultural wastes, potential environmental pollutants.