الفهرس 
Introduction
SchizophyllanOnly 14 pages are availabe for public view
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Abstract
Different experiments were made to select the most favorable conditions for high production of exopolysaccharide from cultivated Pleurotus sapids. Among different growing agar media used in this investigation are Glucose yeast extract peptone (GYP), Potato dextrose broth (PDA), Malt extract Agar (MEA), and Mushroom complete media (MCM); Glucose Yeast Pepton media has proved to be the best media for the mycelial growth and exopolysaccharide production of Pleurotus sapidus followed by PDA with a slight difference. Based on our results, exopolysaccharides in case of shaking is higher than that of static condition.The results reaveled that irradiation of samples with UV light bands lowers the EPS production by the mushroom. Optimization of growth condition for the production of exopolysaccharides produced by Pleurotus sapidus, using placket- Bermann design were obtained. The effect of the variables on EPS production was determined by conducting twenty experiments given by the model. Applying the experimental design showed the maximum production of EPS from Pleurotus sapidus was obtained on trial 15 (+ve concentration of glucose, starch, peptone, yeast extract, KH2PO4, stearic acid and shaking, while -ve concentration of pH, incubation time, temperature, sucrose, omega3 and inoculum size). The results indicated that the presence of high levels of shaking, starch, glucose, KH2PO4, stearic acid, sucrose and maltose in the basal medium positively affected EPS production. These results are confirmed from the Pareto chart, which indicates higher effects of shaking, starch and temperature presented in the upper portion and then progress down to the lower effects. The standardized effect of each factor was calculated using Minitab 16.2.4 (ref USA) software. Among the chosen fermentation variables shaking, starch and temperature were found to be significant. Analysis of the different components showed that the three factors mentioned earlier showed a high percentage contribution to the production of EPS from Pleurotus sapidus. To identify the optimum response region for EPSs production, the significant independent variables (shaking X1, starch X2 and temperature X3) suggested by the Plackett-Burman design were further investigated at three levels (-, 0 and +) in Box-Behnken design. Further-more, the optimal levels of the three variables were estimated using Minitab 16.2.4 (ref USA) software and found to be: temperature (25.2 ºC), shaking (148.9 rpm) and starch (30.1 g/l). Thus, according to the results of the two optimization experiments, an optimum response (EPS production) is predicted under the following fermentation condition gl-1: glucose 40; sucrose 30; starch 30.1; maltose 30; peptone 7; KH2PO4 1; stearic acid 2; yeast extract 5; temperature 25.2 ºC; shaking 148.9 rpm; initial pH 4.5; inoculum size 1disc; and an incubation period of 10 days.