In the present research, nutrient broth (NB) medium was identified to be able to neutralize the antibacterial activity of chitosan and its derivatives. Therefore, an improved test method independent of NB medium was proposed to precisely quantify the antibacterial effectiveness and efficiency of chitosan. The minimum bactericidal concentration (MBC) of chitosan was 60 μg mL^-1 against S. aureus and E. coli, and 0.01% (w/v) chitosan could kill 100% of bacteria within 3 min. From another point of view, the neutralizing efficiency of NB could be tripled by adding 25 g L^-1 of sodium chloride. Then the neutralizing mechanism of NB medium was ascribed to flocculation between chitosan and protein. Adding extra sodium chloride could significantly reduce the size of floccules, and smaller floccules would lose the ability of binding with bacteria directly, showing higher neutralizing rate on the macro scale.

在本研究中，营养肉汤（NB）培养基被鉴定为能够中和壳聚糖及其衍生物的抗菌活性。因此，提出了一种独立于NB培养基的改进的测试方法，以精确定量壳聚糖的抗菌效果和效率。壳聚糖对金黄色葡萄球菌和大肠杆菌的最低杀菌浓度（MBC）为60μgmL ^-1，而0.01％（w / v）的壳聚糖可在3分钟内杀死100％的细菌。从另一个角度来看，通过添加25 g L ^-1可以将NB的中和效率提高三倍氯化钠。NB培养基的中和机理归因于壳聚糖与蛋白质之间的絮凝作用。添加额外的氯化钠可以显着减小絮凝物的大小，较小的絮凝物将失去与细菌直接结合的能力，从宏观上显示出更高的中和率。