Study Of Impacts Of The Cultural Methods And Conditions On The Metabolites Produced Of The Cordyceps Militaris

Cordyceps militaris (L.) Link. is an edible and medicinal fungus bearing various biological activities. Great efforts have been devoted to improve the output of fruiting bodies by solid culture, to improve the contents of cordycepin in liquid fermention and to explore the medicinal efficacy of extracts from both fruiting bodies and mycelium of Cordyceps militaris, while little attention has been paid to the study of how the basic nutrients influence the fruiting body growth and the synthesis and accumulation of bioactive metabolites of Cordyceps militaris.Ten culture mediums were prepared according to the basic nutritional requirements of main substrate ingredient, carbon sources, nitrogen sources and mineral elements and tested in the same condition. The results showed that Medium 2 and Medium 5 are propitious to improve the output of fruiting bodies of Cordyceps militaris. The medium adding Nitrogen Source 4 is more beneficial to improve the output of fruiting bodies than that adding Nitrogen Source 1.Two commonly used methods to detect polysaccharides were compared. The anthrone method was proved to be more accurate than the phenol-sulphuric acid method. The anthrone method has been modified. The color reaction of the modified anthrone method was still stable after four hours; furthermore, the system error was greatly reduced.The extraction condition of polysaccharides was studied using fruiting bodies of Cordyceps militaris. An orthogonal experiment was employed based on four factors that affect the yield of polysaccharides including the extracting time and temperature, extracting times and the solid to solution ratio. The optimized condition to extract polysaccharides was established as extracted two times with 40 times volume of boiling water, two hours for each extraction. The active component analysis showed that the production rate of polysaccharides was up to 15.25% in Medium 4, which was the most advantageous for the accumulation of polysaccharides in the fruiting body of Cordyceps militaris. The production rate of mannite was up to 7.00% in Medium 3, which was the best medium for accumulation of mannite in the fruiting body. Medium 1 was the most advantageous for accumulation of antioxidant substances in the fruiting body, the inhibitate rate of Pyrogallol auto-xidant of the liquid extracts from fruiting body was 62.12%.Combine the above four analyses, the Medium 10 is the best medium to improve the total quality of Cordyceps militaris.