Study On The Extraction And Antibacterial Activity Of Peptides From Cordyceps Militaris

Cordyceps militaris,as a kind of new resource food,has antibacterial,anti-fatigue,anti-tumor,anti-infection,immune regulation,hypoglycemia,anti-aging and other pharmacological effects.The physiological functions of polypeptide on human body mainly include regulating hormone secretion,improving immunity,anti-cancer,anti-oxidation,anti-fatigue,lowering blood pressure,etc.,because of its effect can be used as an intermediate product in the medical care products and other industries.As one of the main directions of deep processing,cordyceps polypeptide can extend the industrial chain of cordyceps militaris and contribute to the sustainable and high-quality development of cordyceps militaris industry.The yield of industrial cultivation of Cordyceps militaris increased year by year,and the further processing of cordyceps militaris has been attracted much attention.The enzymatic hydrolysis method was selected to optimize the enzymatic hydrolysis process of Cordyceps militaris through single-factor test,two-factor three-level test and response surface test.Bacteriostatic tests were carried out on different peptide components to explore their inhibitory effects on common agricultural pathogenic bacteria.The test results are as follows:1.Three conditions of enzymatic hydrolysis were determined by single factor test:enzymatic hydrolysis time,ratio of material to liquid and amount of enzyme.Papain was treated under the condition of enzymatic hydrolysis for 8h when the enzyme dosage was3500 U and the ratio of material to liquid was 1:16.The single factor alkaline protease test was conducted under the condition of enzymatic hydrolysis for 8h when the enzyme dosage was7000 u and the ratio of material to liquid was 1:16.The acid protease single-factor test was conducted under the condition of enzymatic hydrolysis for 8h when the enzyme dosage was3000U-4000 U and the ratio of material to liquid was 1:10,and the acid protease was selected for the next enzyme screening experiment.2.Further enzyme screening was carried out from acid protease,papain and alkaline protease to determine the use of papain and alkaline protease for double enzymatic hydrolysis.Two factors and three levels of papain and alkaline protease were tested respectively to determine that papain was at 55℃ and p H was at 6.Under the condition of 45℃ and p H of10,the alkaline protease was optimized.3.The enzymatic hydrolysis products obtained from single factors were measured by the method,and it was found that they had certain inhibitory effects on root rot,white mycelia anthrax,white silk disease and Pentaphylla cotyledontia.Two factor and three level orthogonal tests were carried out on papain and alkaline protease respectively to determine that papain was at 55℃ and p H was at 6.Under the condition of 45℃ and p H of 11,alkaline protease was the optimized test condition.3.In order to optimize the conditions of complex enzymatic hydrolysis,the response surface orthogonal analysis and polypeptide index were used as the response value,and the temperature,p H and enzyme ratio were tested.When the temperature was 46.6℃,p H was 8.3and enzyme ratio was 7:20,the polypeptide index reached the maximum value of 27.17.4.The enzymatic hydrolysis products obtained from single factors were measured by the cross-sectional method,and it was found that they had certain inhibitory effects on root rot,white mycelia anthrax,white silk disease and Pentaphylla cotyledon blight.The research on cordyceps militaris polypeptides will broaden the follow-up industrial chain of cordyceps militaris,which will contribute to the sustainable and high-quality development of cordyceps militaris industry and meet the development requirements of modern agriculture.