摘要：
通过化学还原法制备了粒径为(20 ± 5) nm、分散性较好、分布均一、没有团聚现象的纳米银颗粒,然后选择3个菌种进行纳米银的体外抑菌试验,并进行红橘浸果试验防治青霉病,研究纳米银对不同菌种的抑制效果和对红橘青霉病的有效防治浓度.结果表明:纳米银对3种供试菌种都有一定的抑制效果,并随着质量浓度的升高而增加.当质量浓度为0.4 mg/mL时,纳米银对金黄色葡萄球菌(Staphyloccocus aureus)和枯草芽孢杆菌(Bacillus subtilis)有较明显的抑制作用,抑制率分别为94.69%和90.25%,而对指状青霉菌(Penicillium digitatum) 的抑制率为71.43%,说明在相同的质量浓度和处理条件下,纳米银对细菌的抑制作用更强,而对青霉菌的抑制作用稍弱.浸果试验结果表明,纳米银质量浓度高于0.4 mg/mL,才能有效防治红橘青霉病,当质量浓度达到0.8 mg/mL时,相对防效为44.64%,低于1000倍液的百菌清(相对防效为59.07%),说明一定质量浓度的纳米银对红橘青霉病有防治效果,虽然不如百菌清,但鉴于其对人体无毒性,在红橘的保鲜中将有较好的应用前景.%To study the inhibitory effect of nano-Ag on different strains and effective concentration on tangerine blue mold,Ag nanoparticles with an average diameter of (20 ± 5)nm,uniform distribution and no agglomeration were prepared by chemical reduction method,and then nano-Ag was set to in vitro control experiments on three strains and tangerine fruit invasion inhibitory test.The results showed that nano-Ag had certain inhibitory effect on the three strains,and the effect was more obvious with the increase of concentration.When nano-Ag concentration reached 0.4 mg/mL,it had a significant inhibitory effect on Staphyloccocus aureus and Bacillus subtilis,with the inhibition rate of 94.69% and 90.25%, while the inhibition rate on Penicillium digitatum was 71. 43%,which showed that under the same concentration and treatment conditions,the inhibition effect of nano-Ag on bacteria was more obvious,and weaker on Penicillium.Three concentrations of nano-Ag were used to test the control effect on tangerine blue mold.Nano-Ag could control the disease effectively when the concentration was higher than 0.4 mg/mL. When the concentration of nano-Ag was 0.8 mg/mL,the control effect was 44.64%,still lower than chlorothalonil 1 000-fold dilution(59.07%).In conclusion,certain concentration of nano-Ag has control effect on blue mold of tangerine fruit,although with a certain difference from chlorothalonil,in view of its non-toxicity to human body,it will show a good application prospect in the preservation of tangerine fruit.
