唾液乳杆菌L3生物合成纳米氧化锌的工艺研究

Biosynthesis of ZnO Nanoparticles by Lactobacillus salivarius L3

摘要:

为获得晶体粒径为纳米级别且对致病菌有明显抑菌效果的纳米氧化锌产品，对乳酸菌生物合成纳米氧化锌的工艺条件进行探索。从断奶7~10 d健康仔猪的粪便中筛选出一株对高浓度锌离子具有耐受性菌株，并以此菌株为模板，氯化锌溶液为原料，分别研究了作用温度、作用时间、发酵后菌液的pH值、氯化锌原液的添加量四个因素对最终产品氧化锌的粒径、转化率及其对致病菌抑菌效果的影响。研究结果表明，当0.25 M ZnCl2底物浓度、体系pH值为7.0，70 ℃水浴温度下作用25 min时得到的氧化锌晶体粒径在70 nm左右，晶体形状均匀，且对大肠杆菌、沙门氏菌以及金黄色葡萄球菌等致病菌的抑菌效果较好，其最小抑菌浓度分别为0.024 mg/mL、0.029 mg/mL、0.016 mg/mL。将纳米氧化锌替代普通锌源添加在动物饲养中能有效改善猪仔生长性能。

Abstract:

In order to obtain the inerratic crystal of ZnO nanoparticles, ZnO nanoparticles was biosynthesized by using Lactobacillus salivarius L3. Lactobacillus salivarius L3 strain was isolated from faeces of healthy weaning piglets weaned at 7~10 d age. Effect of temperature, action time, raw liquor of pH value and the concentration of zinc solution on the synthesis were investigated. The optimum synthesis factors were determined by orthogonal experiment as follows: 0.25 M ZnCl2, pH 7.0, water bath temperature 70 ℃ and reaction time 25 minute. Under the optimum synthesis conditions, the size of the zinc oxide crystal grain were nearby 70 nm. Meanwhile the crystal shape was uniform and had a strong antibacterial capability against E. coli, Salmonella and Staphylococcus aureus. The minimum inhibitory concentration was 0.024 mg/mL to E. coli, 0.029 mg/mL to Salmonella,and 0.016mg/ml to Staphylococcus aureus. Using ZnO nanoparticles instead of normal ZnO into animal feed will effectively enhance the growth performance of weanling pigs.