| Hericium erinaceum Pers. also known as monkey-head mushroom, it belongs to Basidiomycota, Agariomycetes, Polyporales, Hvdnaceae. Hericium. Hericium is a kind of precious food and medicine macrofungi, it has not only nutritious but also great medicinal value.Hericium effect on the treatment of digestive system and generally have anti-tumor, enhance immunity, anti-ulcer, anti-inflammatory, anti-oxidation, anti-aging, neuroprotective effects.The main active substance of Hericium is polysaccharides, in addition to this,it also has oligosaccharides, proteins, fatty acids, terpenoids, phenolic compounds, pyrones etc. Studies have shown that oligosaccharides, streptozotocin, ketones, sterols and other substances of Hericium also has a strong biological activity.Recent studies showed that, sterols and other small molecules have significant roles in lowering cholesterol, anti-oxidation, anti-cancer, anti-inflammatory, prevention and treatment of prostate disease. Sterols have a protective effect on the gastric mucosa, Hericium drugs has a good effect on gastritis maybe related to steroid substances.In this study, ergosterol synthesis were compared on10Hericium strains through the liquid fermentation and cultivation tests. High yield strains of sterols were screened which easy to be cultivated. We studied the effect on sterol synthesis treated by UV treatment salicylic acid and methyl jasmonate. As well as activity changes of enzymes in the process of methyl jasmonate-induced were be tested. We used suppression subtractive hybridization (SSH) as a research tool have constructed the subtractive libraries from Hericium sp. mycelium treated with Methyl jasmonate. Specific gene fragments were selected from the subtractive library to analyze preliminary bioinformatics. Part of the genes were tested by RT-PCR.1. Screening of Hericium erinaceus strains for the high-yielding sterol10strains of wild Hericium erinaceus were chosen to be compare of mycelium yield and ergosterol content of different strains by liquid culture. After comprehensive comparison, the results show that two strains of NO.5and NO.10strains have growth strong capacity and high yield ergosterol of mycelial. Mycelia yield is above average35.9%and35.9%, and ergosterol production is beyond the average30.7%and36.0%, respectively. So, NO.5and NO.10strains can be used as liquid culture strains of choice. In the cultivation NO.5and NO.10Strains have good comprehensive agronomic characters, and they also have has excellent production and commodity of fruiting body. Hence NO.5and NO.10strains can be promoted as commodity cultivars. However synthetic sterol capacity of No.4,6,9strains are strong. Their ergosterol content of fruiting body are relatively high, but the shape are not good.So, the No.4,6,9strains can be used as a medicinal processing varieties.In liquid medium adding dextrin, malt sugar, flour and yeast powder not only can improve the growth of hypha, and also promote the ergosterol content. The ergosterol content in the process of fruit body growth takes on dynamic change, Eterol content of fruit body is the highest in maturity. Reach a mature timely harvest will keep the content of active ingredients.2.Hericium ergosterol metabolic regulation5strains have studied on the effect of sterol synthesis treated by UV treatment, salicylic acid and methyl jasmonate. Comprehensive comparison, SA and MeJA have obvious effects on sterol metabolism. Processing methods are as follows:Condition of culture:culture medium components including potatoes (decortication)200g, malt sugar20g, potassium dihydrogen phosphate3g, magnesium sulfate1.5g, peptone1g, water1000ml. Medium capacity of is100ml per bottle. Static culture2days at25℃after inoculation,then shake culture at25℃,150r/min. In the process of shake culture add different concentrations of SA and MeJA respectively into culture medium.Salicylic acid treatment:At the fifth day after inoculation, add SA into culture medium, the best dosage is100μmol/L. Harvest hyphae at the9th day after inoculation, ergosterol content in mycelia increased by42%.Methyl jasmonate treatment:At the8th day after inoculation, add MeJA into culture medium, the best dosage is50μmol/L. Harvest hyphae at the12d day after inoculation, ergosterol content in mycelia increased by25%.The SSH library of H. erinaceus was constructed under MeJA treatment, and698clones were selected for sequencing. Finally,280high-quality ESTs sequences were obtained in the positive library. After clustering, splicing, and redundancy removal,164unigene were acquired including71contigs and93singletons. The average length of EST is424bp, whereas the library redundancy is41.43%.331high-quality ESTs sequences were obtained in the nagative library.164unigene were acquired, including71contigs and93singletons. The average length of EST is424bp, whereas the library redundancy is41.43%.A total of164ESTs were functionally annotated, and those with functional annotation were GO classified. The classification resultsshowed that genes belonging to translation, ribosomal structure, and biogenesis comprised the largest portion (21.13%), followed by posttranslational modification, protein turnover, and chaperones (12.68%), as well as carbohydrate transport and metabolism and energy production (11.27%). Amino acid transport and metabolic genes, as well as inorganic ion transport and metabolic genes comprised7.04%; cytoskeleton genes,5.63%; cytoskeletal genes,4.23%; and other genes, such as those involved in chromosome structure, lipid transport and metabolism, defense metabolism, intracellular transport, and coenzyme transport and metabolism genes, comprised1.41%. Therefore, the effect of MeJA on H. erinaceum is a complex process involving the activation of numerous genes and protein metabolism.ESTs function annotation and GO classified in negitive library is very little, only six sequences, It is illustrated that most abundantly expressed genes have been suppressed, and only MeJA related gene expression... |
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