壳聚糖对青枯劳尔氏菌生长及其生物膜形成的影响

Effects of chitosan against Ralstonia solanacearum and its biofilm formation

为建立快速检测壳聚糖抑菌效果的方法,研究其对青枯菌生物膜形成的影响并探索其抑菌机理,利用酶标仪检测壳聚糖与菌悬液混合培养物的吸光值,计算抑菌率,同时利用结晶紫染色法对壳聚糖处理后青枯菌生物膜形成能力进行评价,并进行透射电镜观察。结果表明,在壳聚糖浓度低于0.15mg/mL时,随浓度增加其抑菌效果亦显著增加,其浓度超过0.15mg/mL之后,其抑菌效果达到同一水平,最高抑菌率为74.3%;而壳聚糖浓度对青枯菌生物膜形成能力未产生显著影响;透射电镜观察结果显示:壳聚糖通过破坏青枯菌细胞膜抑制细菌生长。

To establish the method for investigating the inhibitory activity of chitosan against Ralstonia solanacearum, and study its effect on R. solanacearum biofilm formation to explore the anti-bacterial mechanism, Microplate reader was used to measure the absorbance value of chitosan mixed with the bacterial suspension cultures, the ability of R. solanacearum biofilm formation was evaluated by crystal violet staining, and R. solanacearum treated with chitosan was observed by transmission electron microscopy （TEM）. At the concentration of chitosan ranged from 0 to 0.15 mg/mL, the higher concentration of chitosan, the better inhibition to R. solanacearum. At the concentration higher than 0.15 mg/mL, the inhibition rate achieved the same level, with the highest rate of 74.3%. The ability of chitosan against R. solanacearum biofilm formation was not significantly different; Transmission electron microscopy showed that cell membrane was destroyed by chitosan to inhibit the growth of bacteria.