蛋清、重组溶菌酶酶学性质及其对小鼠肠道菌群和血清生化指标的影响  

The Enzymatic Properties of Two Kinds Lysozyme and Their Effects on the Intestinal Flora and Serum Biochemical Indicators of Mice

作　　者：田洪源[1] 刘明启[1] 戴贤君[1] 

机构地区：[1]中国计量学院生命科学学院食品系,杭州310018

出　　处：《中国食品学报》2012年第10期16-23,共8页Journal of Chinese Institute Of Food Science and Technology

基　　金：浙江省科技计划资助项目(2008C12053)

摘　　要：目的:研究蛋清、重组溶菌酶酶学性质,探讨两种溶菌酶最佳应用条件;通过小鼠口服试验,研究溶菌酶对小鼠肠道菌群和血清生化指标的影响。方法:在不同温度、pH、人工胃肠液及金属离子条件下,以微球菌为底物,用比浊法测定溶菌酶酶活变化;在小鼠饮水口服溶菌酶(蛋清溶菌酶和重组溶菌酶酶活分别为2500,5000U/mL)后无菌取肠道内容物,通过微生物培养测定肠道菌群的变化;测定不同试验时间的血清总蛋白、尿素氮、甘油三酯、胆固醇的浓度。结果:蛋清溶菌酶最适温度40℃,最适pH6.0;重组溶菌酶最适温度45℃,最适pH6.0;两种溶菌酶在温度超过50℃后活性迅速下降,其中重组溶菌酶下降较快;两种溶菌酶在室温、pH6～9溶液中60min,酶活力均保持在80%以上;在人工胃肠液中,溶菌酶活性迅速下降;Fe3+,Ca2+,K+,Mn2+,Zn2+,Mg2+,Al3+,Cu2+均不同程度地抑制两种溶菌酶活性;动物试验结果表明,两种溶菌酶均能不同程度地降低小鼠肠道金黄色葡萄球菌和粪肠球菌数量,促进双歧杆菌和乳酸杆菌生长,但重组溶菌酶对大肠埃希菌群抑制作用明显(P<0.05),蛋清溶菌酶不明显(P>0.05);不同浓度的两种溶菌酶均能提高血清总蛋白含量,降低尿素氮和胆固醇含量,其中以重组溶菌酶(5000U/mL)饲喂小鼠21d后血清总蛋白、尿素氮、胆固醇同对照组差异显著(P<0.05)。结论:蛋清、重组溶菌酶均具有调节机体肠道菌群,影响血清指标的作用,其中重组溶菌酶的效果更明显,但使用过程需要注意温度、pH、胃液肠液、金属离子对酶活的影响。Objective： The enzymatic properties were studied to determine the optimum condition of activity for egg white lysozyme extracted from the eggs and recombinant lysozyme expressed from the Pichia pastoris including human lysozyme gene. The intestinal Escherichia coli., Staphylococcus aureus, Enterococcus faecalis, Bifidobacterium and Lactobacillus were cultured, and serum biochemical indicators were determined for the mice orally administered with two lysozymes. Methods： Based on the turbidimetry value of micrococcus, lysozyme activity was determined under different reaction conditions（temperature, pH value, artificial gastric and bowel liquid, and common metal ions）; Mice were orally administered with the lysozymes through drinking water including the egg white lysozyme and recombinant lysozyme of 2 500 and 5 000 U/mL. The serum were collected to determinate the concentration of total protein, urea nitrogen, triglyceride and cholesterol through picking eye ball of the mice at the experimental time of 1,7,14, 21 days, then the mice were slaughtered for the intestinal contents taken out in sterile environment to culture the Escherichia coli., Staphylococcus aureus, Enterococcus faecalis, Bifidobacterium and Lactobacillus. Results： Egg white lysozyme exhibited the optimal temperature was 40 ℃, and the optimal pH value was 6.0; Recombinant lysozyme exhibited the optimal temperature was 45 ℃, and the optimal pH value was 6.0. Both lysozyme activity would decline rapidly above 50 ℃,but keep high in the different pH6～9 conditions. Their activities would decline rapidly when both lysozyme were kept in artificial gastric and bowel liquid, only recombinant lysozyme would contain 44.85% activity in artificial bowel liquid after 120 min; The Fe3＋,Ca2＋, K＋, Mn2＋, Zn2＋, Mg2＋, Al3＋, Cu2＋ ions could restrain the lysozyme activity which had no significant difference between two lysozymes（P0.05）. Compared with control group, both lysozyme can restrain the growth of intestinal Staphylococcus aur

关 键 词：蛋清溶菌酶 重组溶菌酶 酶学性质 肠道菌群 血清生化指标 

分 类 号：R151[医药卫生—营养与食品卫生学] TS201.1[医药卫生—公共卫生与预防医学]