Study On Basis Physiology And Key Technology Of Culture Of Pleurotus Nerbrodensis

'Tianshan 2',a cultivar of pleurotus nerbrodensis,was subjected to optimization experiments of nutritional factors and environmental factors in a phytotron at the matemal fungus culture stage and different stages in the whole growth and development period.At the same time,there was studied the law of degradation and use of bastose by the fungus cultured on the cottonseed shell medium,the law of ectoenzyme activity variation in the growth and development period,the physiological mechanism of primordium differentiation promoted by variation of low temperature levels,and the effects of different media on protein and polysaccharide contents in carpopHores.The results are as follows.For growth of p.nerbrodensis,the optimal carbon source is maltose and sucrose;the nitrogen source is yeast paste and peptone Meanwhile,for hyphal growth,the suitable C/N ratio is at 10-40:1;the suitable dose of N ranges 0.15%to 0.27%.Optimal prescription of the medium for culturing maternal fungus spawns is potato 200g, sucrose 20g,yeast paste 5g,MgSO₄ 0.5g,and KH₂PO₄ 2g.The primary materials in the medium suitable for culture of protospecies are sorghum grains,corn grains,and cottonseed shells;that suitable for production of seed fungi are cottonseed shells.The optimal combination of bagging conditions is 24℃-26℃temperature for fungus incubation,moisture content of the medium at60%- 65%,pH5.5-7.5.Whether or not the hyphal underwent postripeness has a very great effect on fungus output and biological transformation,howerer the duration of postripening over 20d has little effects on that.The best conditions for hyphal postripening in p.nerbrodensis are at 25℃of air temperature for 40d of time or at 30℃for 20-30d of duration.Stimulation of primordium differentiation depends on range of temperature and days of duration at low temperature,the feasible air temperature for primordium differentiation ranges 4℃-10℃,and adaptable time of treatment is from 9 to 12d.Both C/N ratio and N%contained in the medium has given effects on p.nerbrodensis in hyphal growth,time of squaring,and biological efficiency.The usefull C/N ratio ranges 28: 1-43:1;the suitable percentage of N is 1.2-1.8,with the optimal being 1.6-1.8.The kind of the main material in the medium markedly affected the growth and development of the culture,using cottonseed shells as the main material resulted in rapid growth of hyphals,early occurrence of buttons,and high biological efficiency.For hypHals,low temperature stimulated cellulose,hemicellulase and acidic protease to be clescended in activity;while high temperature increased the activity of amylase,lacease, neutral protease,and glucogen degradase.Low temperature led to glucogen degradation in hypHals and promoted protein synthesis and metabolism.Postripening process of hyphals was accompanied by accumulation of nutrients in hyphals.When the postripening has been completed,the protein,polysaccharide,and total soluble sugar were raised by 180%,52.4%,and 55.6%,resp.The activity variation of ectoenzyme had some clear periodic steps in the whole growth and development period.The activity of cellulose and hemicelulase retained low levels at the hypHal growth stage,sharply went up after formation of primordial,and beoan to tarnish after carpopHores harvested.Laccase and amylase kept relatively stable in activity at the whole hypHal growth stage,furthermore.They had higher activity than cellulose and hemicelulase at the early stage of hyphal growth,with the activity of the two enzymes dropping to different degrees in the period of carpopHore growth and development,and further decreqsing after carpopHores harvested.In acidic protease and neutral protease,the activity appeared more stable at the hypHal growth stage,then significantly increased at the carpopHore growth stage. In the whole growth and development period,acidic protease owned obviously higher activity than neutral protease.In the whole growth and development period,acidic protease owned obviously higher activity than neutral protease.Both C/N ratio and N level in the medium affected ectozyme activity..The C/N ratio from 28:1 to 54:1 and nitrogen ranging from 1.4%to 1.6%simulataneausly met the demands by cellulose,hemicellulase,and laecase.In the whole growth and development period,p.nerbrodensis mainly degraded bastose and used it for growth per se,at the reproduction stage,it used the same as the chief carbon source,and nonlignin was principally used by it at hyphal growing and hyphal postfipening. Our experiments suggested that in the whole growth and development period,cellulose, hemieellulose,lignin,and bastose were degraded by 40.24%,32.06%,34.61%,and 35.52%, resp.The degradation of bastose was found to be evidently periodic,i.g.,the degradation rate was lower at hyphal growing and hyphal postoripening,but clearly quickened at reproductive stage.There existed a difference in order of bastose members to be preferentially used at different stages.On the first 35 days,lignin got priority in use by the cultured fungus; cellulose was used in priority at postripening;hemicellulose at primordium differentiation cellulose was chiefly used again at carpophore growing.