Studies On The Antimicrobial Activity And Composition Analysis Of Artificial Culture Of Cordyceps Cicadae

Cordyceps cicadae(Miq.)Massee is a parasitic fungal,which infects the nymph of cicada.In this paper,the antimicrobial activity,the volatile components and the main components of the artificial culture of Cordyceps cicadae were investigated deeply and systematically.The main contents includ liquid,solid and fruiting body culture of asexualstrain RCEF 6202 of Cordyceps cicadae.To elected the best indicator bacteria for antimicrobial activity,inhibition test(plate method)of three different artificial cultures of Cordyceps cicadae was tried.Active substances from the ethyl acetate extract were purified by high performance liquid chromatography.The chemical structure of the active compound was identified by physio-chemical properties and spectral data(HPLC-MS and NMR).The volatile components were analyzed with gas chromatography-mass spectrometry(GC-MS),which extracted by the method of simultaneous distillation and extraction(SDE)in the three different artificial cultures of Cordyceps cicadae cultured.The main components of three different artificial cultures of Cordyceps cicadae were analyzed and compared.The result of antimicrobial activity test showed that the water and methanol extracts of the mycelia from plates culture(MPTC),the mycelia from shake culture(MSKC)and the fruiting bodies of Cordyceps cicadae(AFCF)were no inhibiting effect on Bacillus subtilis,Escherichia coli,Staphylococcus aureus,Bacillus thuringiensis,Aspergillus niger and Candida albicans.The ethyl acetate extract of MSKC and MPTC of Cordyceps cicadae was slight inhibition effect on Aspergillus niger and Candida albicans.The ethyl acetate extract of the fermentation broth of Cordyceps cicadae was also inhibition effect on Aspergillus niger and Candida albicans,but the inhibition effect of Candida albicans is the best and most obvious.So Canidia albicans was the best indicator for studying antimicrobial activity.To inhibit Candida albicans as an index,active substances from the ethyl acetate extract were purified by high performance liquid chromatography,and the active substance obtained with high purity.The antifungal active substance of the extract was identified as myriocin by NMR and mass spectrometry analysis.GC-MS analysis demonstrated that there were 18,13 and 16 kinds of volatile components identified in MSKC,MPTC and AFCF,respectively.The volatile components of three kinds of artificial cultures of Cordyceps cicadae mainly contented alcohols,olefinic compounds,ester compounds,phenolic compounds,ether compounds and acid compounds.The common volatile components of three kinds ofartificial culture of Cordyceps cicadae were 1-octene-3-alcohol,2-decene-5-lactone,butylhydroxytoluene,palmitic acid and 3-tert-butyl-4-hydroxyanisole.The total of five compounds accounted for 69.85%,77.11%and79.87% in the whole volatile substances respectively.The five kinds of compounds played a leading role for the strong odor of Cordyceps cicadae.Composition analysis showed that there were plenty and similar quantity of crude protein in three kinds of artificial cultures of Cordyceps cicadae.The content of crude fat in descending order were MPTC(2.65 g / 100g),MSKC(2.50 g / 100g)and AFCF(1.64 g / 100g).The contents of polysaccharide in MPTC(7.22g/100g)were similar to those in MSMC(7.53g/100g),but less than that in AFCF(8.66g/100g).The content of adenosine in MSKC was the highest,and higher than that in AFCF and MPTC.The content of cytosine in AFCF was significantly higher than that in MPTC and MSMC.The content of amino acid in MSKC(34.97g/100g)were similar to those in AFCF(34.91g/100g),but slightly higher than that in MPTC(34.27g/100g).The content of essential amino acids in descending order were AFCF(12.82 g/100g),MSKC(11.42g/100g)and MPTC(10.56g/100g).There were high levels of the mineral elements of Mg,Ca,Al,Se,et al in three kinds of artificial cultures of Cordyceps cicadae,and the content of Mg,Se rich particularly.