Abstract:In order to study the optimum technology and antibacterial activity of mulberry leaf polysaccharide separated and purified by macroporous resin.Mulberry leaf polysaccharide extracted by ultrasonic-microwave collaboration was used as raw material，the specific adsorption rate，adsorption rate and desorption rate of 8 kinds of macroporous resins were investigated，the best purified resin was selected，the adsorption and desorption conditions were investigated and optimized，the optimum purification process parameters were determined by single factor test，and the bacteriostatic effect of mulberry leaf polysaccharide before and after purification was investigated by Oxford cup method.The results showed that the optimal process parameters were as follows：sample loading solution concentration was 3.0 mg/mL，pH 4.0，sample loading flow rate was 1.5 BV/h.The volume fraction of the desorption liquid ethanol was 65%，pH 6.0，elution velocity was 1.5 BV/h，and elution volume was 90 mL（3.0 BV）.Through this process，the purity of crude mulberry leaf polysaccharide was increased from 11.34% to 57.46% and 4.07 times.The bacteriostatic test results showed that the concentration of polysaccharides in mulberry leaves was greater than 1.0 mg/mL，which had different degree of inhibitory effect on the activities of Escherichia coli，Salmonella and Staphylococcus aureus，and the antibacterial effect was significantly enhanced after purification.