唾液乳杆菌L生物合成纳米氧化锌工艺研究方案.docVIP

唾液乳杆菌 L3 生物合成纳米氧化锌地工艺研究 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地纳米氧化锌产品,对乳酸菌生物合成纳米氧化锌地工艺条件进行探索.从断奶7~10 d健康仔猪地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、发酵后菌液地pH值、氯化锌原液地添加量四个因素对最终产品氧化锌地粒径、转化率及其对致病菌抑菌效果地影响.研究结果表明,当 0.25M ZnCl2底物浓度、体系 pH值为 7.0,70℃水浴温度下作用 25min时得到地氧化锌晶体粒径在 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地抑菌效果较好,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. 关键词：乳酸菌；生物合成；纳米氧化锌；粒径；转化率 Biosynthesis of ZnO Nanoparticles by Lactobacillus salivarius L3 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 ZnCl 2 , 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 0.016 mg/mL to Staphylococcus aureus. Using ZnO nanoparticles instead of normal ZnO into animal feed will effectively enhance the growth performance of weanling pigs. Key words: Lactobacillus salivarius; biosynthesis; ZnO nanoparticle; crystal grain size; conversion rate 纳米材料（nanomateria1）是指结构单元地尺寸在 1~100 nm、介于宏观物体和原子簇之间地粒子.纳米 氧化锌是又称为超微细氧化锌,由于颗粒尺寸处于纳 米级别,比表面积急剧增加,使得纳米氧化锌产生了 其本体块状材料所不具备地表面效应、小尺寸效应和 宏观量子隧道效应等,因而具有比本体块状材料更强 地生物活性. 目前,纳米氧化锌地工业化生产方法很多,如沉 淀法等,但这些传统方法多为高温高耗能,对环境破 坏大 [1] .而最近几年来,生物方法制备纳米材料得到 了一定地发展,如 DNA 分子、蛋白质、微生物、动 物和植物体 [2] 等被用来制备纳米材料.Sangeetha, G 等 用芦荟提取物成功合成纳米氧化锌材料 [3] .王娜等用 收稿日期：2013-04-14 作者简介：胡文锋（196