摘要
目的:从杏鲍菇子实体与海带中分离的63株乳酸菌中鉴定出产细菌素Lcn972A的菌株,并对细菌素编码基因进行克隆与基因序列分析。方法:采用生物信息学手段对已报道的细菌素Lcn972A编码基因进行分析比较,设计引物,分别以各乳酸菌基因组DNA为模板,利用PCR克隆技术克隆出细菌素Lcn972A的基因,利用生物信息学工具对其核酸序列和预测的蛋白序列进行分析。结果:在63株乳酸菌的基因组样品中有15组被克隆出目的条带,其中杏鲍菇乳酸菌A15与海带乳酸菌CX2样品PCR产物条带清晰稳定性好,经鉴定两样品的乳酸菌株为乳酸乳球菌(Lactococcus lactis)。对克隆的细菌素Lcn972A基因测序结果表明该基因序列全长276 bp。生物信息学分析显示该基因编码91个氨基酸,分子量大小22843.3 u,等电点5.33,氨基酸序列为亲水性,二级结构主要由α-螺旋、无规卷曲和延伸链组成。结论:从分离自杏鲍菇子实体乳酸乳球菌A15与海带乳酸乳球菌株CX2的细菌素编码基因及氨基酸序列与报道的有所不同,可能是新的细菌素,该细菌素的抗菌特点有待进一步的研究。
Objective： In this study,bacteriocin Lcn972A- producing bacteria were screened from 63 strains of lactic acid bacteria isolated from Pleurotus eryngii fruit body and Thallus Laminariae. Subsequently,gene for this bacteriocin was cloned by PCR methods and analyzed by bioinformatics tools. Method： Primers were designed based on the results of bioinformatics analysis of reported genes for lcn972 A. Subsequently,genes for Lcn927 A were isolated from the genomic DNA of 63 strains of lactic acid bacteria respectively. Finally,the nucleotide sequence and predicted protein sequence were analyzed by a series of bioinformatics tools. Result： Genes for Lcn927 A were isolated from 15 genomic samples among 63 strains of Lactic acid bacteria.Two of the positive stains were characterized as Lactococcus lactis from Pleurotus eryngii fruitbody A15 and Thallus Laminariae CX2. The result of sequencing showed that the full length of the Lcn927 A gene was 276 bp,which coded for 91 amino acid residues,with molecular weight of 22843.3 u,theoretical PI of 5.33,hydrophilic amino acid,the secondary structure of protein consist of α- helix,random coil and extended strand.Conclusion： The nucleotide sequence and predicted protein sequence of present Lcn927 A gene of Lactococcus lactis A15 and CX2 isolated from Pleurotus eryngii fruitbody and Thallus Laminariae were different from those that hadbeen publicly reported,and the antimicrobial properties of this gene need to be identified in the future study.
出处
《食品工业科技》
CAS
CSCD
北大核心
2015年第21期187-191,共5页
Science and Technology of Food Industry
基金
国家自然科学基金资助(31071837
31272217)
广东省攻关项目资助(2013B010404041)
