| Volvariella volvacea is a typical high-temperature edible fung,which can not be preserved at low temperature,and will be degradation when continuous subculture the mycelium.In this paper,the related enzyme activity,production trait and the variation of fruiting body nutrients in continuous culture of V.volvacea were studied.The primary culture and subculture mycelium of V.Volvacea was investigated by using comparative metabolomics analysis.The results are as follows:1.The activity of filter paper enzyme,CMCase,laccase and cellobiase in S0-S19 was determined.The results showed that the activity of four enzymes decreased along with the increase of subculture in number of times.Filter paper enzyme decreased from 0.833 ± 0.012 U/mL to 0.232±0.005 U/mL;CMCase decreased from 0.416 ± 0.010 U/mL to 0.097 ± 0.006 U/mL;laccase decreased from 98,188±2.084 U/L to 26.706 ± 0.918 U/L;cellobiose decreased from 0.369 ± 0.019 U/mL to 0.089 ± 0.005 U/mL.2.Laboratory cultivation test of was conducted.The results showed that S0-S12 are capable of fruiting,and S13-S19 could not yield.It is indicating that the mycelium have lost the fruiting ability when it was continuous subcultured for 12 months.Moreover,the primordium formation time and production cycle of strain S0-S12 were gradually prolonged from 7 ± 0.514 d and 21±0.514 d to 17±0.707 d and 30±0.707 d,respectively,with the increase of the number of subcultures.The fresh weight and efficiency of biological also showed a decreasing trend,and the biological efficiency decreased from 27.033 ± 0.954%to 4.304±0.452%.3.The nutrient content of the obtained fruiting body was determined,the results showed that the contents of polysaccharides and protein decreased from 30.352 ± 1.046%and 24.042±1.378%to 11.108±0.543%and 9.680±0.387%,respectively.The content of flavonoids and polyphenols was not significantly different.The contents of Mg and Cu were the most and the least,respectively.And the contents of Mg and Cu were not significantly changed in the process of degradation.The other mineral elements decreased with the increase of subculture times.4.According to the results of the cultivation experiment,S0-S12 was used as the fruiting group and S13-S19 as the non-fruiting group,and the comparative metabolomics was analyzed.Among the biomarkers found and initially identified,the specific compounds of the fruiting group include Glycocyamine,Phosphonoacetate and unknown compounds at 4.62 min;the specific compounds of the non-fruiting group include Guanosine,Prolinamide,4-guanidinobutanoic acid,L-Glutamic acid,Thioguanine and 11.44 min of unknown compounds.The remaining biomarkers are contained in all strains,but their contents are different.The mechanism of Luteolin-3’,7-di-O-glucoside,Guanosine and Thioguanine in the process of continuous subculture was preliminarily elucidated. |
