杨树桑黄多糖提取条件优化及其抑菌活性研究OA北大核心CSTPCD

[Objective]The aim is to optimize the extraction process of Sanghuongporus vaninii polysaccharides(SVP),explore the antibacterial mechanism of SVP,and provide reference for the development of natural antimicrobial agents.[Method]Based on single factor experiments and response surface analysis,we optimized the process of extracting polysaccharides by water extraction and alcohol precipitation,and improve the polysaccharides extraction yield.By measuring the minimum inhibitory concentration,growth curve,and enzyme activities,we studied the antibacterial activity of SVP against Escherichia coli and Staphylococcus aureus.[Result]When the extraction temperature is 86℃,the time is 1.6 h,and the ratio of material to liquid is 1:24 g/mL,the extraction yield of polysaccharides is 4.07%.The minimum inhibitory concentrations of polysaccharides against E.coli and S.aureus are 2.000 mg/mL and 1.500 mg/mL,respectively.Compared with the negative control group,the extracellular alkaline phosphatase(AKP)activity of E.coli and S.aureus increased by 3.7 times(P＜0.05)and 2.6 times(P＜0.05),the enzyme activity of β-galactosidase increased by 6.2%(P＜0.01)and 7.3%(P＜0.01),the ΔOD 260nm increased by 60%(P＜0.01)and 1.2 times(P＜0.01),the intracellular Na+/K+-ATPase activity decreased by 28.9%(P＜0.001)and 34.8%(P＜0.001),the Ca2+-ATPase activity decreased by 43.2%(P＜0.001)and 35.6%(P＜0.001),the ATPase activity decreased by 20.1%(P＜0.001)and 34.6%(P＜0.001),the malate dehydrogenase(MDH)activity decreased by 23.5%(P＜0.001)and 28.7%(P＜0.001),and the succinate dehydrogenase(SDH)activity decreased by 17.9%(P＜0.01)and 13.8%(P＜0.01),respectively.[Conclusion]After response surface optimization,the actual extraction yield of SVP is 5.71%higher than the predicted extraction yield,and SVP has a strong inhibitory effect on E.coli and S.aureus.Its mechanism of action may be related to the destruction of bacterial cell membranes,inhibition of energy metabolism enzymes,etc.