应用16S rDNA全序列测序技术鉴定生鲜乳中的细菌种类
Identification of bacterial species from raw milk by 16S r DNA sequencing
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摘要: 采用玻璃珠法提取生鲜乳中分离的34株细菌基因组DNA,用细菌通用引物(27f/1492r)PCR扩增16S r DNA片段并测序,与Gen Bank数据库同源序列比对,系统发育树聚类分析,并结合形态学和生理学特征确定了34株菌的种属地位。结果表明,共鉴定出16个种属。3个生鲜乳样中细菌种类及其分布特点不同。其中1号样有7种细菌,以Acinetobacter sp.(不动杆菌属)为主,2号样有6种细菌,以Klebsiella sp.(克雷贝氏杆菌属)为主,3号样有6种细菌,分布较为分散。从致病性来看,分离菌株主要为条件致病菌或腐败菌,无烈性致病菌。Abstract: Using glass bead method to extract the genomic DNA of 34 bacterial strains which were isolated and purified in raw milk.Common primer 27 f /1492 r was used to amplify 16 S r DNA fragments. The PCR products were sequenced.Then the 16 S rRNA sequences were compared with Gen Bank database homologous sequence and the phylogenetic tree was constructed through clustering analysis. The phylogenetic status of 34 species of bacteria were determined combined with morphological and physiological characteristics.The results showed that 16 kinds of species were identified.Bacterial species and its distribution characteristics were different among three raw milk samples,where the 1st sample had 7 kinds of bacteria,mainly Acinetobacter sp; the 2nd sample had 6 species,mostly Klebsiella sp.; the 3rd sample had 6 species of bacteria,the distribution was more dispersed. From the pathogenic point of view,all strains were opportunistic pathogens or spoilage,no virulent pathogens.