Studies On Carbon And Nitrogen Nutrient Physiology Of Pleurotus Eryngii

Most edible fungi fell into saprophytic fungus whose growth required nourishment absorbed from the external world. Carbon and nitrogen were two major nutrient element. During the cultivation of pleurotus eryngii, the choice of carbon and nitrogen sources. suitable C/N and N% played an important role in mycelial growth and fruitbody growth with high yield and high quality . But the reports on carbon and nitrogen physiologic of pleurotus eryngii were less. In this experiment , pleurotus eryngii 1 was used as testing material. The utilization of carbon sources,nitrogren sources, C/N and N% and the law of extracellular laccase, catechol oxidase, CMCase and hemicellulase produced by mycelia were studied. The results laid a foundation for further researching nutrient physiologic of pleurotus eryngii. Meanwhile the outcomes provided an important reference for selecting excellent medium.1 At the stage of cultivating mother culture, the ultilization of pleurotus eryngii 1 with six kinds of carbon sources including sucrose, lactose, D-fructose, soluble starch, maltose and glucose and eight kinds of nitrogen sources including yeast extract, peptone, NH4C1, NR₄NO₃ (NH4)2S0₄, KNO₃, CH₃COONH₄ and urea in potato synsetic medium were studied. The producing law of extracellular enzyme in different carbon sources medium and nitrogen sources medium were also researched. The results showed that the appropriate carbon source was soluble starch and the appropriate nitrogen sources were yeast extract and peptone. During the mycelium growth, extracellular enzyme activity of laccase, catechol oxidase, CMCase and hemicellulase were related to some kind of carbon source or nitrogen source, while were not correlated to mycelial growth amount. When C-source and N-source were glucose and yeast extract respectively ,it was beneficial to the production of laccase. As to catechol oxidase, glucose and CH3COONH₄ were appropriate C-source and N-source. CMCase, appropriate C-source and N-source were fructose and (NH)₂SO₄ Hemicellulase activity was the most high as C-source andN-source were lactose and2 When mother culture was cultivated, as far as pleurotus eryngii 1 was concerned, more suitable C/N was 20:1?0:1 among seven treatments from 10:1 to 66.8:1; more suitable N% was 0.12%⁰.16% among seven treatments from 0.12% to 0.36%. Four kinds of extracellular enzyme need different C/N and N% during mycelium growth period. Laccase needed lower C/N which it was 20:1 or so. While catechol oxidase ,CMCase and hemicellulase needed higher C/N.Their activity were higher at 40:1 or so. As to N%, four kinds of extracellular enzyme activity were higher at 0.28% or so.3 Using cotton seed hull, wood-sawdust and wheat bran as major components of cultivation medium, more suitable C/N for pleurotus eryngii was 29.6:1?4.6:1 among seven treatments from 24.6:1 to 54.6:1. More suitable N% was 1.1% or so among seven treatments from 0.7% to 1.9%.4 The effects of C/N and N% of cultivation medium on four kinds of extracellular enzyme activity were major, but the effect on changing law of enzyme activity was minor. The change of enzyme activity was related to fruitbody development. At the stage of vegetative growth, the extracellular laccase and catechol oxidase activity were higher. At fruitbody development stage, two kinds of enzyme activity decreased. Extracellular CMCase and hemicellulase activity were lower at vegetative growth stage.The enzyme activity began to increase when it entered the stage of reproduction growth stage. The activity peaks appeared coincidentally with the mature period of the fruitbody. Four kinds of extracellular enzyme activity showed a tendency to decline after fruitbody were harvested.5 After determining mycelial mean growth rate, days of primordium formation and biological efficiency of culture medium with different C/N and different N% treatments, the conclusions of correlation testing showed that there was not significant correlation between C/N, N% and mycelial mean growth rate respect...