Investigation of productions manganese peroxidase and laccase enzymes from white rot fungus

White rot fungi are unique in the ability to degrade all components of lignocellulose due to their capability to synthesize the oxidative extracellular enzymes. In this thesis, ligninolytic enzyme production such as laccase (Lac) and manganese peroxidase (MnP) by submerged fermentation (SF) of white rot fungus, Pleurotus ostreatus HK-35 was investigated depending on cultivation mode, different concentrations of copper (0.5; 1; 2.5; 5 mM) and manganese (0.15; 0.29; 0.5; 0.75; 0.1 mM) ions, starch concentrations (1, 5, 10, 20 g/L) as a carbon source and Tween-80 (0.025; 0.05; 0.1 percent, v/v) concentrations as a non-ionic detergent with respect to incubation time at degree of 25. In addition, protein, pH, biomass, reducing sugar and nitrogen levels were also determined. The production patterns of these ligninolytic enzymes were studied during the growth of the organism for a period of 20 days in the stationary cultivation. The highest Lac and MnP activities were obtained as 2900 U/L and 2637.5 on day 10 and 12, respectively. Therefore, optimal growth conditions were specified as in presence of 10 g/L glucose, 0.5 mM Cu (II) and 0.29 mM Mn (II). pH levels were observed approximately at 7-8. In addition, decreases in reducing sugar and nitrogen levels were observed on the third day. In presence of starch (10 g/L) as a carbon source, the obtained highest Lac and MnP enzyme activities were decreased as 49 and 25 percent, respectively. With regard to use of different Tween 80 concentrations, no significant effect on the Lac and MnP enzyme productions by P. ostreatus were observed.