【作者】 照日格图；

【导师】 哈斯苏荣； 吉日木图；

【作者基本信息】 内蒙古农业大学 ， 基础兽医学， 2007， 硕士

【摘要】 双峰驼乳中富含多种营养素外还含有许多生物活性成分,其中乳铁蛋白在食品配方和药物研究等方面均起着重要作用。本研究通过等电点沉淀、硫酸铵沉淀和凝胶层析等方法,从内蒙古阿拉善双峰驼乳中分离纯化乳铁蛋白,通过考马斯亮蓝方法测定不同分离纯化方法所获得的乳铁蛋白含量,并用SDS-PAGE电泳分析了其纯度和分子量。结果表明,通过两次硫酸铵沉淀-两次SephadexG-100柱层析分离得到纯度为91%的驼乳乳铁蛋白(CLF)。再经凝胶成像系统分析确定其分子量为81.42KD。采用试管二倍稀释法测定了驼乳铁蛋白的抗菌活性,结果表明CLF对E.coli的最小抑菌浓度(MIC)为3mg/mL,对S.aureus的最小抑菌浓度为2mg/mL,且与溶菌酶联合应用,则能明显增强其抗菌作用。乳铁蛋白的抗菌活性还与其铁饱和度密切相关,随着铁饱和度的增加其抗菌活性明显下降。葡萄糖、蔗糖、麦芽糖、牛血清白蛋白(BSA)、尿素、硫酸铵在0～10mg/mL,乳糖和可溶性淀粉在0～4mg/mL,酪蛋白在0～1.2mg/mL的质量浓度范围内,对CLF的抗菌活性影响不大。而NaCl或KCl的浓度为25～100mmol/L,MgCl2或CaCl2的浓度为1.0～5.0mmol/L时,乳铁蛋白的抗菌活性则会明显降低。不同热处理和不同pH值条件对乳铁蛋白的抗菌活性亦有显著影响:在一定的温度范围内,随着热处理温度的增加乳铁蛋白的抗菌活性明显下降,即经较低温度加热处理后CLF能很好的保持其活性;而经较高温度加热处理会使CLF变性并失去抗菌活性。不同pH条件下的抗菌试验结果表明,当pH值在7.5～8.0时CLF的抑菌效果最好。更多还原

【Abstract】 Multi-nutritional components and some bioactive components were contained in Bactrian camel milk.One of the most important components—lactoferrin was purified by centrifugation and ammonium sulfate precipitation from the Bactrian camel colostrum.The purity of lactoferrin was reached over 91% after Sephadex G-100 molecular chromatography. Moreover, lactoferrin was analyzed qualitatively and quantitatively by Coomassise Brilliant Blue and SDS-PAGE.The results showed that the lactoferrin’s molecular weight is 81.42KD.The antibacterial activity of lactoferrin was studied by using test tube double dilution method.The MIC of camel lactoferrin against E.coli and S.aureusis were 3mg/mL and 2mg/mL, respectively.Combined use with Lysozyme will strengthen CLF antibacterial activity.CLF antibacterial activity is obviously reduce with its iron saturation increase. Glucose, Sucrose, Maltose, BSA, Urea, Ammonium Sulphate at concent ration of 0～10mg/mL, Lactose and Starch at concent ration of 0～4mg/mL and Casein at concent ration of 0～1.2mg/mL have no significant effects on the antibacterial activity of lactoferrin. Its antibacterial effectiveness was reduced in the presence of NaCl or KCl at concent ration of 25～100mmol/L, MgCl2 or CaCl2 at concentration of 1.0～5.0mmol/L.The different pH conditions and heat treatment of CLF also have significant influence on its antibacterial activity. The results indicated that CLF is very stable at low temperature and at high temperature will lose activty.The CLF was most active under slightly alkaline(7.5～8.0)conditions.更多还原