| Hypsizygus marmoreus,also known as baiyu mushroom,seafood mushroom,was loved by people for its9 unique flavor,good taste and crab flavor.Juncao technology,was a compre-hensive technology which utilizing wild or artificial cultivation Juncao,such as Miscanthus floridulus,Dicranopteris dichotoma,Pennisetum purpureum,Pernisetum sinese,as raw ma-terial to cultivate edible and medical mushrooms.Selenium plays an important physiological function in human body and edible fungus contains a large number of selenium.The enrich-ment of selenium content in sporocarp via the combination of mineralized selenium and cell activity of macromolecular material.As now widespread lack of selenium intake,Hypsizygus marmoreus can be a food source for selenium intake,thus has a broad application prospect.In this paper,we had selected a suitable cultivation formula for Juncao cultivation by the Tertiary screening method,through the analysis and researchment of different cultivation materials for H.marmoreus extracellular enzyme,conversion rate,production and quality,providing a the-oretical basis for promoting H.marmoreus cultivation at the same time,.Through the plate assay,liquid fermentation,cultivation experiment and Selenium fruit body quality analysis,preliminary studied the characteristics of H.marmoreus Se-enriched,which laid foundations of theory,application and promotion of the Se-enriched H.marmoreus.The results were as follows:1.Taking advantages of the three-level system screening method,we got a suitable for-mula for the industrialized production of H.marmoreus.The formula include:36.5%of Pen-nisetum sinese;36.5%of D.dichotoma;20%of bran;5%of corn flour;1%of Calcium car-bonate;1%of lime;with a natural pH.This formula made a unit yield of 312 g per bag,the biological efficiency was 80.73%,and its cultivation time was 115d.The research results of different raw materials for H.marmoreus cultivation showed that,when H.marmoreus was cultivated using Juncao,it can improve the hyphae growth and enhance biology efficiency,and shorten the cultivation cycle and increase effective flower number of fruiting body.If there were high proportion of Juncao in culture medium,the bacteria packages were more light,and the length of stipe was more thin and more soft,then it was difficult to transport.So it can enhance the storage and transportation when added appropriate proportion of sawdust and cot-tonseed in the culture medium of Juncao.The components of the fruiting body were higher,and its ash,rough protein and amino acids were for 9.62%,26.75%and 18.78%,respectively.About the amino acid composition,the proportion of delicious amino acid was 4.63%,the ratio of delicious amino acid was 24.65%,while levels of heavy metals were within the re-quirements of green food.All in all,the raw materials of saw dust and cotton seed hull with proper proportion of Juncao can improved the H.marmoreus sporocarp content of ashes,crude protein,umami amino acidsy and the proportion of umami amino acidsy in total amino acid,as well as perfected its taste.2.Effect of different cultivation substrates on extracellular enzyme activities of H.mar-moreus results showed that,the activity of H.marmoreus mycelium secretion of lignin en-zymes(laccase,Mn-peroxidase)reached the maximum at the ripening stage of mycelium in each culture material,and the activity of non-ligninolytic enzyme reached the maximum at the mycelial reproductive stage;The activity of the same extracellular enzymes,secreted by HK marmoreus at different culture mediumwere disparate in different growth period.The chang-ing trends of lignin enzymes activity were imparity,the trend of Non-lignin enzyme activity were essentially same.The results indicated that the change of the activity of H.marmoreus mycelium secreted enzyme was closely related to growth period and periodical.The activities and changing tendency of lignin enzymes were related to the mycelium growth stage of H.marmoreus and the components of formula,meanwhile,the changing tendency of non-lignin enzymes activities of HK marmoreus were determined by the mycelium growth stage of HK marmoreus and could be affected by different formulas.3.A study on characteristics of H.marmoreus mycelium tolerance to selenium.We de-tected the different kinds of H.marmoreus mycelium tolerance to selenium by using the plat-ing method.The results showed that:The concentration that were less than or equal to 50μg/mL of Exogenous selenium was good for the growth of H.marmoreus mycelium.The pro-moting effect varied between different myceliums,but compared with the CK,there were no significant differences.The concentration that were more than or equal to 75 μg/mL of Exog-enous selenium could block the growth of H.maurmoreus nycelium.And the maximum con-centration to selenium was between 150 μg/mL to 200 μg/mL,at that condition,the form of H.marmoreus colony was incomplete,the colour of mycelium become shallow or yellow,the growth of aerial hyphae would be blocked;The result of reduction of culture showed that the inhibition of growth could be recovered.According to the regression functions between sele-nium concentrations and mycelial growth rate,the results showed that the strain of 9600 was sensitive to the exogenous selenium.We can observe the change of H.marmoreus form the stress of selenium by using optical microscope and scanning electron microscopy;We could find that the shape of H.marmoreus mycelium was even thickness,strong full,more hyphaes with branches,mycelium had smooth surface,lock joint and structure obviously with the low concentration of selenium.And the hyphae of H.marmoreus mycelium were different thick-ness,hyphae shrivel in long flat bar,lock joint structure collapse and dry,the surface uneven,a similar bamboo-like structure would be found,gradually replaced by globular conidium hy-phae tip,part of the branch became alienation conidium or chlamydospore with the high con-centration of selenium;The fermentation results of selenium-enriched liquid from different bacterial strain showed as follows:When the selenium concentration in fermentation liquor was 5 μg/mL,the amount of dry matter of the fermentation hypha reached the most highest;When the selenium concentration in fermentation liquor was 15 μg/mL,the content of water-soluble protein and polysaccharide got the most highest value;The content of selenium-en-riched and the selenium enrichment efficiency varies between different bacterial strains.When the selenium concentration in fermentation liquor were less than or equal to 25 μg/mL,the highest content of selenium-enriched and the highest selenium enrichment efficiency were all higher than that of the No.10 Baiyu;The highest content of selenium-enriched of the two bacterial strains were 1471.14 μg/g and 844.98 μg/g;while the highest selenium enrichment efficiency of the two bacterial strains were 72.76%and 71.10%.4.The cultivation experiment showed that Se-enriched cultivation could increase the number of commodity mushroom flowers,coarsen the stipe,and improved the conversion rate,and advanced the mushroom cycle.But different formulas had different effects on the produc-tion.The composition determination of selenium-enrich fructification showed that crude pol-ysaccharide content of Se-enriched H.marmoreus slightly higher than that of the control group.The fresh sample,ash content,total amino acid content of fructification were lower than that of the control group.Crude protein content was lower than or close to the control group,but the selenium had little impact on total sugar,crude fat content,irregular,and the heavy metal content detection were lower than the national standard.In short,the Se-enriched cultivation can increase the production of H.marmoreus,but cause a decline to overall quality.The H.marmoreus selenium-rich ability,multiples,distribution in different formula showed that it had a strong ability of Se-enriched,the resistance ability and substrates could influence its se-enriched ability.The concentration of selenium were set for 0～320 mg/kg,selenium content at about 0.46～52.29 mg/kgH.marmoreus samples,that was 2.7～307.6 times than the ordi-nary on.In the No.24 formula,selenium content at about 1.18～84.92 mg/kg H.marmoreus samples,that was 6.94～499.53 times than the ordinary one.Fructification selenium content was positively correlation to selenium concentrations in substrates,selenium concentrations in cap is higher than stipe,and there is no influence in different substrates. |
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