1株宽宿主谱的阪崎肠杆菌噬菌体生物特性分析及其在乳制品中的应用  

Characterization of a Wide Host-Range Cronobacter sakazakii Bacteriophage and Its Application in Milk Products

作　　者：李虹娇 黄梓聪 吴希阳[1] 丁郁 唐书泽[1] LI Hongjiao;HUANG Zicong;WU Xiyang;DING Yu;TANG Shuze(College of Science&Engineering,Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学理工学院,广东广州510632

出　　处：《食品科学》2021年第6期164-170,共7页Food Science

基　　金：广州市对外科技合作项目(201704030096);粤港联合创新项目(2016A050503031);“十三五”国家重点研发计划重点专项(2018YFC1602500)。

摘　　要：以阪崎肠杆菌菌株ATCC25944为宿主菌从河涌水中分离1株噬菌体TBC-1,具有较宽的阪崎肠杆菌宿主范围。电镜形态学及生物特性结果显示:此噬菌体衣壳为二十面体,具有可收缩性尾部;该噬菌体的最佳感染复数(multiplicity of infection,MOI)为0.001,一步生长曲线显示其潜伏期20 min,爆发期50 min;爆发量为100 PFU/cell;该噬菌体在温度区间40~50℃及pH 4~10之间可以保持其效价稳定;对阪崎肠杆菌有较好的裂解杀菌效果,并且MOI越高抑制效果越好。全基因组测序分析显示:该噬菌体的基因组为双链DNA,全基因组分子质量85313 bp,平均GC含量40.65%,共有118个蛋白编码区,24个tRNA。应用结果显示,TBC-1对牛乳中2种阪崎肠杆菌的抑制效果:室温(25℃)培育3 h,在MOI为106时,能将102 CFU/mL菌抑制到检出限以下;TBC-1对乳粉中2种阪崎肠杆菌的抑制效果:在25℃与37℃培育3 h,ATCCBAA894菌量均减少到检出限以下,在25℃培育3~12 h,ATCC25944菌量均在检出限以下。本研究表明噬菌体TBC-1具有宽宿主谱系特性、稳定的裂解杀菌以及在牛乳与乳粉中对不同的阪崎肠杆菌均有良好的抑制作用,有潜力成为阪崎肠杆菌生物抑制剂。Bacteriophage TBC-1 was isolated from sewage using Cronobacter sakazakii ATCC25944 as the host.Observation under electron microscope revealed that TBC-1 displayed a contractile tail;the shape of its capsid was an icosahedron.It had a wide host range.The multiplicity of infection(MOI)of the bacteriophage was 0.001.The one-step growth curve showed that its latent time was 20 min;the outbreak period was 50 min;the number of outbreak was 100 PFU/cell.TBC-1 maintained its high titer at 40–50℃and pH 4–10.In addition,C.sakazakii showed stronger lytic ability at higher MOI.The complete genome was 85313 bp in length and the content of GC was 40.65%.It had 118 protein coding sequences(CDSs)and 24 tRNAs.The bacteriostatic effect of the bacteriophage on C.sakazakii ATCC25944 and ATCCBAA894 in milk products was investigated.It turned out that after incubation at 25℃for 3 h with MOI=106,both strains at 102 CFU/mL in milk were inhibited to below the detection limit.After incubation at 25 or 37℃for 3 h,ATCCBAA894 was inhibited to below the detection limit;after incubation at 25℃for 3–12 h,ATCC25944 was inhibited to below the detection limit.The results showed that the phage exhibited a wide host range against C.sakazakii and had good bacteriostatic efficacy in both milk and milk powder,demonstrating its potential to be a bio-control agent against C.sakazakii in foods.

关 键 词：阪崎肠杆菌 裂解性噬菌体 宽宿主谱 抑菌效果 

分 类 号：Q939.48[生物学—微生物学]