微囊化沙门菌SP4噬菌体的制备及其缓释特性分析

通过采用阳离子醚化淀粉/海藻酸钠/黄原胶/纳米TiO₂/壳寡糖为原料制备微囊化SP4噬菌体，为控制沙门菌感染提供生物制剂。选用沙门菌SP4噬菌体，采用液滴法来制备微囊化SP4噬菌体，并对其效价、阳离子醚化淀粉浓度、海藻酸钠浓度、黄原胶浓度、壳寡糖浓度、pH稳定性、热稳定性、模拟胃液稳定性、模拟肠液释放行为以及保存稳定性进行分析。结果显示，当阳离子醚化淀粉浓度为2.4%、海藻酸钠浓度为2%、黄原胶浓度为1%、壳寡糖浓度为0.6%时，微囊化SP4噬菌体微球外形规则，包封率为97.5%，在pH5.0~8.0、温度10~30℃、模拟胃液pH2.0、0~30 min和pH3.0、0~150 min噬菌体保持较高的生物学活性，模拟肠液中4 h，噬菌体完全释放，4℃环境下保存6周噬菌体效价无明显降低。综上表明，微囊化沙门菌SP4噬菌体显著提高了噬菌体的稳定性和缓释性能，其耐酸特性利于抵御胃酸的分解，具有应用于生物防治的潜力，为进一步采用多因素试验制备微囊化沙门菌SP4噬菌体奠定了基础。

Preparation of Microencapsulated Salmonella SP4 Bacteriophage and the Study on Its Slow-release Performance

Microencapsulated SP4 phage was prepared by using cationic etherified starch/sodium alginate/xanthan gum/nano TiO₂/chitosan oligosaccharide as raw materials, to provide biological agents for controlling Salmonella infection. Salmonella SP4 phage was used to prepare microencapsulated SP4 phage by droplet method, and its titer, cationic etherified starch concentration, sodium alginate concentration, xanthan gum concentration, chitosan oligosaccharide concentration, pH stability, thermal stability, simulated gastric juice stability, simulated intestinal juice release behavior and preservation stability were analyzed. The results showed that when the concentration of cationic etherified starch was 2.4%, the concentration of sodium alginate was 2%, the concentration of xanthan gum was 1%, and the concentration of chitosan oligosaccharide was 0.6%, the shape of microencapsulated SP4 phage microspheres was regular, and the encapsulation efficiency was 97.5%. The phage maintained high biological activity in the range of pH 5.0-8.0, temperature 10-30℃, simulated gastric juice pH 2.0 for 0-30 min and pH 3.0 for 0-150 min. The phage was completely released after 4 h in simulated intestinal juice, and the phage titer did not decrease significantly after 6 weeks at 4℃. The results show that microencapsulated Salmonella SP4 phage significantly improves the stability and sustained-release performance of phage, its acid resistance is conducive to resisting the decomposition of gastric acid, and has the potential to be used in biological control, which lays a foundation for the further identification of microencapsulated Salmonella SP4 phage by multi factor test.