Spent Pleurotus Eryngii Substrate Is Used In The Technical Research Of The New Cultivation Cycle Of Pleurotus Ostreatus

With the rapid expansion of edible mushroom industry,the amount of spent mushroom substrates also increases rapidly,how to effectively use spent mushroom substrates become an urgent problem.In China,Pleurotus eryngii as the 6th most produced edible mushroom species in terms of annual production,the amount of bran produced each year was amazing,and Pleurotus eryngii,which was harvested only once,had a spent mushroom substrates rich in high nutrients.Integrating the materials through new formulations and methods,and using the spent mushroom substrates for the new cultivation cycle of the Pleurotus ostreatus had the dual advantages of reducing production costs and environmental impact,and can effectively alleviate the problems of raw material shortage,rising costs and geographical restrictions in Pleurotus ostreatus cultivation.Given the complexity of the components in the spent mushroom substrates,this study focused on the biological and agronomic parameters involved in the use of Spent Pleurotus eryngii substrates in the new cultivation cycle of the Pleurotus ostreatus,in order to achieve the most effective use of Spent Pleurotus eryngii substrates without incurring excessive costs harmful to the process itself,while maintaining the quantity and quality of the mushrooms produced.The specific studies were as follows:(1)Research on the effects of different nutrient components of culture materials on the growth,yield,biological efficiency and nutritional quality of mycelium of Pleurotus eryngii and Pleurotus ostreatus,to clarify the biological and agronomic parameters and to determine the best formulation of culture substrate for Pleurotus eryngii and Pleurotus ostreatus.The experimental results showed that the growth rate,full bag time and emergence time of mycelium of Pleurotus eryngii were significantly correlated with the carbon to nitrogen ratio(C/N);Carbon(C)source had obvious influence on the mycelial growth rate of Pleurotus eryngii,the addition of bagasse was beneficial to accelerate the growth rate of Pleurotus eryngii and shorten the time of full bag and mushroom emergence;The addition of bagasse as a C source and soybean meal as a nitrogen(N)source to the substrate was effective in increasing the yield of Pleurotus eryngii;The composition of the materials all had significant effects on the nutrient composition of the substrates of Pleurotus eryngii.The addition of bagasse was beneficial to increase the total sugar content and crude fat in the substrates of Pleurotus eryngii,and the addition of corn flour was beneficial to increase the total sugar content in the substrates of Pleurotus eryngii,while the addition of soybean meal and corn flour could increase the crude protein,crude fat and ash content in the substrates of Pleurotus eryngii.The best performance of Pleurotus ostreatus yield,bioefficiency,and concentration of mushroom emergence at C/N of 20:1;C/N had no significant effect on the mycelial growth of Pleurotus ostreatus;C/N had a significant effect on the nutrient composition of Pleurotus ostreatus,with a C/N of 20:1 favoring the formation of crude protein in the substrates,a C/N of 40:1 favoring the formation of crude fat in the substrates,and a C/N of 35:1 favoring the increase of ash content in the substrates.The optimized formula of the substrate for Pleurotus eryngii at 100% new material was:corn cob 40%,bagasse 9%,wheat bran 18%,soybean meal 7.5%,corn meal 7.5%,lime2%,light calcium carbonate 2%,and C/N 35:1,based on factors such as mycelial growth rate,growth potential,full bag time,emergence time,yield,biological efficiency,and substrate quality;The optimized formula of Pleurotus ostreatus substrate was: corn cob 15%,wood chips 5%,wheat bran 20%,cotton seed husk 50%,lime 2%,light calcium carbonate 2%,C/N 20:1.(2)Safety evaluation study on the reuse of spent Pleurotus eryngii substrates.The experimental results showed that the aqueous extract of Pleurotus eryngii had no inhibitory effect on the mycelial germination and growth rate and growth of Pleurotus ostreatus;The alcoholic extract of Pleurotus eryngii had a significant inhibitory effect on the mycelial germination of Pleurotus ostreatus,and the inhibitory effect increased with the increase of alcoholic extract concentration.The content of heavy metals in the spent Pleurotus eryngii substrates all meet the requirements and can be used as cultivation substrate for secondary use.The content of Hg,Cd,As and Pb in the fruiting body of Pleurotus ostreatus,Pleurotus eryngii,Flammulina velutiper,Lentinus edodes and Auricularia auricula with spent mushroom substrates were all far below the limits specified in GB 2762-2022,indicating that the spent Pleurotus eryngii substrates was safe to be used in the new cultivation cycle of mushrooms and did not pose any risk to food and environment.(3)To carry out research on the composition and cellulose changes of the substrate before and after cultivation at different substitution levels and the effects on the growth,yield,biological efficiency and quality of the mycelium of the Shiitake mushroom when the spent Pleurotus eryngii substrates was used in the new cultivation cycle of the Pleurotus ostreatus.The test results showed that the addition of spent Pleurotus eryngii substrates could promote the synthesis of threonine,serine,glutamic acid,glycine,valine,methionine,isoleucine,leucine,histidine and lysine in the fruiting body of Pleurotus ostreatus,and was more conducive to the concentration of mushroom emergence of the Pleurotus ostreatus;The highest yield and biological efficiency of the Pleurotus ostreatus was achieved at 30% of the spent Pleurotus eryngii substrates substitution amount,while the yield and biological efficiency of the mushroom decreased significantly after 60% of the substitution amount;There was no significant effect on the agronomic traits of Pleurotus ostreatus with the amount of spent Pleurotus eryngii substrates substitution below 70%.Spent Pleurotus eryngii substrates replacement was highly significantly negatively correlated with C/N,hemicellulose,cellulose,and lignin with correlation coefficients of-0.640,-0.541*,-0.946**,and-0.959**,respectively,while it was highly significantly positively correlated with N content The correlation coefficient was 0.706.When spent Pleurotus eryngii substrates was used as the substrate for the new cultivation cycle of the Pleurotus ostreatus,the best overall effect was achieved when the substitution amount was 50%,and the average increase in revenue per bag was 0.33 yuan compared to 100% new material,taking into account the reduction of production cost and environmental impact.