Study On The Regularity Of Four Mushrooms Absorpting Heavy Metal And Pesticide Residue

One non-negligible issue in edible fungi industry is that residue of heavy metal and pesticides exceeds the standard.Accordingly,the quanlity safety of edible fungi is not only related to the interest of consumers but also affect the development of the whole industry.In this study,Hypsizigus marmoreus,Auricularia auricula and Pleurotus ostreatus were taken as experimental material.By adding lead,cadmium,mercury and arsenic at different concentration to the culture substrate,the degradation dynamics of them in different edible fungus fruiting body were studied.The results showed that heavy metal contents in fungus fruiting bodies were significantly correlated with heavy metal contents in cultivation material.However,heavy metal enrichment ability of different fungi varied greatly.Hypsizigus marmoreus was able to significantly enrich mercury,arsenic and cadmium,with enrichment coefficients of 27.54 and 22.76 for arsenic and cadmium,respectively,which were higher than one of Auricularia auricula and Pleurotus ostreatus.As for lead,Hypsizigus marmoreus did not show significant enrichment ability,with enrichment coefficient of 0.007 at concentration as high as 50mg/kg.The enrichment abilities for the three edible fungi were Pleurotus ostreatus>Auricularia auricula>Hypsizigus marmoreus。Logistic regression model was built based on heavy metal content in media and residue content of heavy metal in fruiting body.According to the limit of heavy metal residue described in pollution-free food and green-food standard,the established logistic model were used to calculate the safe limit of heavy metal level in fungi cultivation material in order to product safety mushroom,which may provide useful guidance for quality control during edible fungi productionMoreover,three kinds of fungi were taken as experimental material to investigate the degradation rates of nine pesticides during fruiting body growth.The effects of different spraying methods and dosages of these pesticides on fruiting body growth were also researched.The results showed that chlorpyrifos,carbendazim,thiophanate methyl and cypermethrin have negative effect on fruiting body growths.When pesticides were added into cultivation media,Hypsizigus marmoreus and Pleurotus ostreatus were unable to fruit at chlorpyrifos concentration of 2-4mg/kg.A uricularia auricula and Hypsizigus marmoreus were unable to fruit at carbendazim concentration of 4mg/kg.Hypsizigus marmoreus and Auricularia auricula were unable to fruit at thiophanate methyl concentration of 2mg/kg and 4mg/kg,respectively.The contents of residue of thiophanate methyl in fruiting body of Pleurotus ostreatus exceeded the standard when thiophanate methyl and carbendazim concentration were added into cultivation media as high as 4mg/kg,while that of bifenthrin in fruiting body of Auricularia auricula exceeded the standard when bifenthrin concentration was as high as 2mL/kg～4mL/kg.Degradation capacities for fruiting body of different fungus varied greatly when pesticides were sprayed during fungi producing.Among them,pesticides degradation rate for Pleurotus ostreatus fruiting body to pesticides was fastest.The half-life for the nine pesticides ranged from 9.5h to 31.5h.Pesticides degradation rate for Auricularia auricula’s fruiting body was slowest.The half-life for the nine pesticides ranges from 0.74 day to 14.75 days.Additionally,we found that dichlorvos was degraded easily,whose half-life was shorter than 1d in fruiting body of all three edible fungi.When pesticides were sprayed during fruiting,the residues of pesticides in fruiting body were exceed the standard in all test groups except the dichlorvos test group.Additionally,Pleurotus ostreatus was susceptible to pesticides.Dichlorvos and chlorpyrifos have negative effect on fungi growth,even causing the death of fruiting body.