Production of some ligninolytic and hydrolytic enzymes with solid state fermentation

In this thesis, the productions of ligninolytic and hydrolytic enzymes, laccase, manganese peroxidase, lignin peroxidase, carboxymethyl cellulase, xylanase, exoglucanase, β-glucosidase, from Pleurotus eryngii were optimized using peach and cherry wastes under solid state fermentation conditions. Firstly, the chemical compositions of these wastes from fruit juice industry were determined in terms of cellulose, lignin, reducing sugar, total carbohydrate and protein, nitrogen and some metals. According to chemical analysis, these wastes could be named as lignocellulosic. P. eryngii was incubated on both peach and cherry agroindustrial wastes by solid state fermentation for thirty days without-with pretreatment conditions. The lignocellulosic substrates were pretreated with dilute acid and alkaline solutions, hot water before incubation. The used pretreatment methods had generally negative effects on these enzymes productions. Also, the effects of different compounds; copper, iron, Tween 80, ammonium nitrate and manganese, and their variable concentrations on ligninolytic and hydrolytic enzymes productions were investigated in detail. In the second part of the thesis, the purifications of laccases were carried out by ammonium sulfate precipitation, anion exchange and gel filtration chromatographies, respectively due to their biotechnological and industrial importance. The laccase fractions with high yield and high purification factor were subjected to electrophoretic analysis. Also, the purified laccases were partially characterized. The effects of selected chemical agents such as ethylenediaminetetraacetic acid, phenylmethane sulfonyl fluoride, iodoacetamide, β-mercaptoethanol and sodium azide on the purified laccase activities were also investigated. In the third part of the thesis, the decolorization of some azo dyes was carried out by crude extracts and purified laccases from both cultures, and the effects of the dyes on laccase enzymes stabilities were investigated in addition to optimization of productions, purification and characterization studies. Finally, Fourier transform infrared spectroscopy analyzes were performed to determine whether there were the changes of methyl orange dye.