Effects Of Four Kinds Of Heavy Metals On The Growth And Food Safety Of Edible Mushroom

Nowadays industrial and agricultural scraps are always used as medium in edible mushroom industry,and it is identified that heavy metals are much easier to be accumulated in edible mushroom fruit bodies.As a result of this,heavy metal pollution has seriously influenced the quality and food safety of edible mushroom.So to keep a proper level of heavy metal content in medium and covering soil can improve the quality of edible mushroom and also make a great sense to the development of edible mushroom industry.In this research,the main cultivars such as Pleurotus ostreatus,Agaricus bisporus,Agaricus brunnescens and Agaricus blazei Murrill were used as the experimental species,and three methods were taken by selecting different mediums, or adding Pb,Cd,Hg and As of different concentrations in mediums,or adding Pb,Cd, Hg and As of different concentrations in covering soil.Effects of heavy metal content in medium or casing soil on the product security of edible mushroom had been analyzed.The capacity of edible mushroom fruit bodies in accumulating Pb,Cd,Hg and as had been researched,the results were as follow:1,The experiments of adding single heavy metal of different concentrations in the medium of Pleurotus ostreatus showed that the growth rate of hypha was no significantly influenced by Cd,Hg,As of low concentrations in medium.When the concentration achieved a certain level,the inhibition arose and the effects on biological efficiency increased first,and then decreased.In this experiment,both the growth rate and biological efficiency of hypha were improved under the designed level of Pb concentration.2,On the condition of no air or water pollution,the correlation between heavy metal content in Pleurotus ostreatus fruit bodies and medium was positively.The heavy metal accumulation capacity of Pleurotus ostreatus from strong to weak ranked as follow:Cd,Hg,As,Pb.3,The heavy metal content in medium of different raw materials was in a great difference,and the edible safety of Pleurotus ostreatus fruit bodies could be basically assured through selecting raw materials of no industry pollution.4,The heavy metal accumulation ability of edible mushroom had a great relationship with its varieties and characteristics.The heavy metal accumulation ability in covering soil was different among three Agaricus varieties.In the situation of no medium and covering soil pollution,the Cd accumulation characteristic of Agaricus blazei Murrill was the most prominent,and its absorbing ability to mercury was strong,at the same time,Cd and Hg content was far beyond the limit of《Hygienic standard for edible mushroom》and《Green food Edible mushroom》. Moreover,after adding heavy metals of certain concentrations in covering soil,the Cd, Hg,As content of Agaricus blazei Murrill all exceeded the limitation of hygienic standard,as well as the Hg content of Agaricus brunnescens.And the heavy metal accumulation capacity of AS2796 was the weakest,the four kinds of heavy metals content of which were all within the limitation of Green food.