Effects Of Carbon And Nitrogen On Liquid Culture And Extracellular Enzyme Activity Of Pleurotus Geesteranus

Pleurotus geesteranus Singer,known as Lentinus edodes,is a kind of Pleurotus ostreatus belonging to Pleurotus of Agarical.It originates in Chamo Province of southern India.The fresh mushroom has rich protein and abundant amino acids.It can provide eight essential amino acids for human body,possessing very high nutritional value.Liquid culture is a kind of culture method that inoculates microorganisms directly into liquid medium,and continuously oscillates or stirs them to make microorganisms grow and propagate uniformly in liquid medium.Compared with traditional production methods,liquid culture of edible fungi has many advantages,such as simple production process,more pure liquid strains,neat mushroom production,shorter production cycle and lower cost.In liquid culture of edible fungi,carbon and nitrogen sources are two types of main nutrients with different requirements of edible fungi.The control of the amount of carbon and nitrogen sources is very significant for the growth of mycelia and the yield and quality of fruiting bodies.Based on the liquid culture of Pleurotus 169 and Pleurotus ostreatus 206-1,the effects of different carbon sources,nitrogen sources,carbon to nitrogen ratios and nitrogen content on the growth of mycelium in liquid culture of Pleurotus ostreatus were studied.And the activity of four extracellular enzymes of amylase,hemicellulase,laccase and carboxymethylcellulase in the liquid culture of two kinds of Pleurotus ostreatus was investigated due to changes in carbon and nitrogen sources.The results showed that the best carbon source for Pleurotus ostreatus 169 was lactose,and the best carbon source for Pleurotus ostreatus 206-1 was glucose;The best nitrogen source for both Pleurotus ostreatus was bran.The carbon-to-nitrogen ratio of liquid culture for the two strains of Pleurotus ostreatus 169 and Pleurotus ostreatus 206-1 is 20:1;When the nitrogen content is 0.10%-0.25%,it is most suitable for liquid culture of two kinds of Pleurotus ostreatus.In the liquid culture process,the carbon source,nitrogen source,carbon to nitrogen ratio and nitrogen content in the medium are four kinds of extracellular enzymes secreted by the hyphae of Pleurotus ostreatus,namely amylase,hemicellulase,laccase and carboxymethyl.The activity of the cellulase can have a certain effect,and the activity of the extracellular enzymes of different varieties of Pleurotus ostreatus is also different.The carbon and nitrogen sources that are beneficial to the growth of the hyphae of Pleurotus ostreatus are not necessarily conducive to the secretion of extracellular enzymes,and there is no necessary connection.