液熏罗非鱼片加工过程中微生物群落的PCR-DGGE 分析

为弄清液熏罗非鱼片加工过程中微生物污染的源头，以进一步防控产品的微生物污染提供依据。应用基于细菌16S rDNA 的PCR-DGGE(PCR-denaturing gradient gel electrophoresis，PCR- 变性梯度凝胶电泳)技术分析液熏罗非鱼片主要加工关键环节的微生物群落结构，提取样品中的细菌总DNA，对细菌的16S rDNA 的V6～V8 区段进行PCR 扩增后，进行变性梯度凝胶电泳(DGGE)，对DGGE 图谱进行微生物多样性分析，对主要条带进行序列分析并构建系统发生树。结果表明：10 个条带所代表的优势种很可能来源于以下几个属：巨型球菌属(Macrococus)、微球菌属(Micrococus)、肠道细菌属(Enterobacter)、假单胞菌属(Pseudomonas)、弧菌属(Vibrio)、突柄杆菌属(Prosthecobacter)、布特菌属(Buttiauxella)，其中肠道细菌属、微球菌属、假单胞菌属和弧菌属细菌都具有使产品腐败的潜能。本研究表明：液熏罗非鱼片中呈现微生物多样性，PCR-DGGE 技术可用于研究液熏罗非鱼片加工过程中的微生物群落结构及变化，且具有一定的优越性。

PCR-DGGE Analysis of Bacterial Community during Processing of Liquid-smoked Tilapia

In order to understand the origin of bacterial contamination in liquid-smoked tilapia fillet during processing and provide evidence for controlling bacterial contamination, bacterial community and diversity were analyzed by PCR-DGGE (PCRdenaturing gradient gel electrophoresis). The total bacterial DNA was extracted from samples and V6-V8 regions of bacterial 16S rDNA gene were then amplified to establish phylogenetic tree. Results indicated that the bacterial community could contain Macrococus, Micrococus, Enterobacter, Pseudomonas, Vibrio, Prosthecobacter and Buttiauxella. Pseudomonas, Micrococus, Vibrio and Enterobacter had potential to spoil liquid-smoked tilapia fillets. Therefore, PCR-DGGE used for analyzing bacterial community and diversity during processing of liquid-smoked tilapia was feasible and convenient.