Studies Of Environment Control And Physiological Test During Pleurotus Tuoliensis In Mycelium Physiological Maturity Period

Pleurotus tuoliensis is an important edible fungus with independent intellectual property rights in China and has great market potential,but the cultivation technology for Pleurotus tuoliensis is not perfect,especially the lack of fundamental research on the Mycelium Physiological Maturation Period?MPMP?.In this study,the mycelium maturation and process control during MPMP were systematically studied.Meanwhile,the effects of different ripening temperatures and different lights on the activity of three extracellular enzymes and ergosterol content were analyzed,and metabonomics methods were used to discover metabolite differences between different treatments,screening the related differential metabolites and analyzing their changing trends,in order to explore the physiological changes of mycelium during MPMP and establish the evaluation method for mycelia maturity,which can provide a scientific basis for the improvement of cultivation technology.In this study,the mycelium during MPMP was subjected to different temperatures and lights treatment,then the mushroom bud number,fruiting body shape and average fruiting body yield under different treatments were analyzed statistically,and the best environmental conditions for the MPMP were optimized.The ergosterol content and the activity of three extracellular enzymes in mycelia under different treatments were determined.The variation curves of ergosterol content and extracellular enzymes activity were used to infer the optimal length of MPMP and enzyme indicator.Pleurotus tuoliensis during MPMP were subjected to the treatments of five different temperatures?17?,20?,23?,26?and 29??or four different lights for 35 days,then the fruiting management was performed.The results showed that when the temperature was 17?,the quality and size of fruit body was stable,and the fruiting time was very concentrated.The average mass of individual fruit body was 201.91g,and the biological efficiency was 70.35%,which was significantly different from other temperature treatments.The results of light treatments showed that the yield of fruit body was the highest under blue light,the average mass of individual fruit bodies was 182.91g,and the biological efficiency was 63.73%,but there was no significant difference with other light treatments.The optimal temperature during MPMP was preliminary determined to be 17?.The activities of carboxymethylcellulase,hemicellulase and amylase in Pleurotus tuoliensis mycelium during MPMP were studied at five temperatures and it was found that carboxymethycellulase activity reached the highest value on the 15^th day,with the highest value of 4.02 U at the temperature of23?,and there was a significant difference among different treatments.On the 35^th day,the activity of this enzyme was lower than that in the early stage,and the difference was not significant at different temperatures.The amylase activity peaked around the 5^th day,and the treatment of 23?rendered the highest enzyme activity of 5.83U.The activity of hemicellulase during MPMP was very small,and the temperature and illumination have little effect on its activity.Therefore,it was preliminarily determined that amylase activity can be used as a reference indicator for the mycelial maturation during MPMP.The ergosterol content during MPMP was determined by HPLC,and the results showed that the ergosterol content was relatively high at the temperatures of 17?,20?,23?and 26?,which was significantly higher than that at 29?.The results of light treatment showed that ergosterol content had no significant change in the early stage of MPMP,but gradually decreased after the 30^th day,the ergosterol content reached the highest of 5.73mg/mL.However,the change of ergosterol content under dark treatment was just opposite,it gradually increased after the 30^th day,and reached its maximum of5.13 mg/mL on the 35^th day.These results showed that the ergosterol content will reach its peak in advance under light conditions,and the MPMP may be reduced to 30 days.The metabolites difference in samples from treatment C1?MPMP,0 d?,treatment C2?MPMP 35 d,17??and treatment C3?MPMP 35 d,29??were analyzed by Gas chromatography-Mass spectrum combinated with unsupervised principle component analysis?PCA?and supervised orthogonal least squares-discriminant analysis?OPLS-DA?.The PCA analysis results of the metabolomics data matrix showed that there are separation trends between different treatments and analysis quality control samples.The OPLS-DA model can separate samples from treatment C1,treatment C2 and treatment C3.The criterion for screening metabolites between treatments was that the VIP value of the first principal component for the OPLS-DA model was>1,and the p value returned by the Student's t-test was<0.05,meanwhile the fold change?FC?of differential metabolites was calculated.A total of 117 kinds of metabolites were screened out,wherein organic acids,amino acids and alcohols accounted for 64%of the total metabolites,other metabolites were amines,phenols,sugars and ketons.