Selenium Enrichment And Polysaccharide Cataining Se Production Rise In Ganoderma Lucidum Liquid Fermentation

Both Ganoderma lucidum and selenium play an role in prevention and treatment of many diseases. The researches on the activities of Ganoderma lucidum and selenium have been deeply performed, but it still stays on the primary stage in the world to combine the Ganodermd lucidum and selenium into Se-enriched Ganoderma lucidum. Polysaccharide containing selenium in Ganoderma lucidum is made of both natural and artificial synthesized Fungi polysaccharide enriched selenium, in which inorganic selenium in the medium can be transformed into organic selenium by Ganoderma lcuidum. Research results have showed that polysaccharide containing selenium in Ganoderma lucidum has better pharmaceutical activities than polysaccharide or selenium. Therefore, it is more practical to study se- polysaccharide in Ganoderma lcuidum.The results of this study were as follows:(1) good strains were screened and the effect of selenium on the growth and metabolism of Ganoderma lucidum was studied, a strain of Ganoderma japonicum with high selenium resistance, higher extracellular polysaccharide and more suitable for liquid fermentation was chosen, then three strains were chosen to study the effect of selenium on the growth and metabolism of Ganoderma lucidum: Ganoderma sp. With the highest selenium resistance, Ganoderma japonicum with highest selenium enrichment rate and Ganoderma atrum with lower biomass, but highest selenium accumulation per gram of the mycelia. And it was showed that Se-enrichment ability was related to strains, cultivation time, biomass and the pH of the fermentation liquid.(2) Optimizing the fermentation conditions of Ganoderma japonicum. The effect on the mycelia biomass and extracellular polysaccharide of nutrient demands and environment conditions of Ganoderma japonicum were studied by single factor experiments and orthogonal test respectively. The experimental results showed that a fermentation medium suitable for Ganoderma japonicum to produce high extracellular polysaccharide was confirmed. The optimum formula of fermentation liquid culture medium is that the optimum concentration of Na2SeO3 was 20mg/L, corn flour 60g/L, yeast extract 2.0g/L, KH2PO43.0 g/L, MgSO41.5g/L, and the fermentation conditions are as follows: initial pH 5.0, temperature 30℃, 75mL liquid medium in 250mL flask, inoculation rate 6%, rev of 200r/min, and culturing for 6 days. When the Ganoderma japonicum is cultured in optimum nutrient demands and environment conditions as required above, it was found that the maximum mycelia biomass is 32.26g/L, extracellular polysaccharide cataining Se is 2.84g/ L.(3) Extracting conditions of intracellular polysaccharide from the dry mecelia of Ganoderma japonicum by ultrasonic extraction were optimized by Central Composite Design concept of response surface methodology. The results showed that the optimum conditions of the extraction were as follows: ultrasonic extraction power 396.00W, solid-liquid rate 1:75, time 50.50min, temperature 61.00℃, and the extraction rate was 3.45%, and also verified with the check experiments, the extraction rate is 3.38%. Compared with the traditional hot water extraction method, the extraction rate was increased by 28.0%, and the method is simpler, more convenient. The organic selenium accumulation per gram of intracellular polysaccharide captaining Se is 72.35±0.018μg.