摘要
以冰鲜的三文鱼片为研究对象,利用形态学观察和16S r DNA序列分析法探究其在0℃冷藏过程中腐败菌的变化规律,并结合VITEK2微生物自动鉴定系统对其特定腐败菌进行分离和鉴定。结果表明:0℃冷藏三文鱼片在贮藏初期(第0 d)的腐败菌主要为葡萄球菌属(Staphylococcus sp.)、假单胞菌属(Pseudomonas sp.)、片球菌属(Pediococcus sp.)、微球菌属(Micrococcus sp.)、气单胞菌属(Aeromonas sp.)、肉食杆菌属(Carnobacterium sp.)及部分鞘氨醇单胞菌属(Sphingomonas sp.)。随贮藏时间的延长,腐败菌菌相逐渐单一,葡萄球菌属、片球菌属、微球菌属呈明显的下降趋势;气单胞菌属及鞘氨醇单胞菌属完全消失;肉食杆菌属变化较小,而假单胞菌属呈上升趋势且到贮存后期数量占绝对优势。腐败菌的PCR产物经测序后通过NCBI数据库比对,并经MEGA5.05软件构建系统发育树分析及微生物自动鉴定仪共同鉴定,确定荧光假单胞菌(Ps.Fluorescens)为冷藏三文鱼片的优势腐败菌。
Chilled fresh salmon fillets were used for the study; the differential prevalence of spoilage bacteria during storage at 0 ℃ was analyzed by morphological observations and 16 S r DNA sequence analysis. In addition, the specific spoilage bacteria were separated and identified using the VITEK 2 automated microbial identification system. The major spoilage bacterial species identified in salmon fillets stored at 0 ℃ during the start of storage(day 0) were Staphylococcus sp., Pseudomonas sp., Pediococcus sp., Micrococcus sp., Aeromonas sp., Carnobacterium sp., and Sphingomonas sp. The phase of spoilage bacteria gradually became unitary with the increase in storage time; a significant decrease was observed in the numbers of Staphylococcus sp., Pediococcus sp., and Micrococcus sp., whereas the Aeromonas sp. and Sphingomonas sp. disappeared completely over time. No significant changes were observed in the Carnobacterium sp; on the other hand, there was a gradual increase in the proportion of Pseudomonas sp., leading to its predominance during the end of the storage time. The sequences, amplified by polymerase chain reaction(PCR), were compared against the sequences present in the National Center for Biotechnology Information(NCBI) database; the phylogenetic tree constructed using the MEGA 5.05 software was used for analysis, and the automated microbial identification system was utilized for all measurements. These results identified Pseudomonas fluorescens to be the dominant spoilage bacterium in refrigerated salmon fillets.
出处
《现代食品科技》
EI
CAS
北大核心
2015年第4期36-41,共6页
Modern Food Science and Technology
基金
国家自然科学基金(31301572
31301418)
中国博士后科学基金(2014M552302)
"十二五"国家科技支撑计划(2012BAD29B06)
高等学校博士学科点专项科研基金(优先发展领域)(20113326130001)
关键词
三文鱼片
腐败菌
16S
RDNA
发育树
荧光假单胞菌
salmon fillets
spoilage bacteria
16S rDNA
phylogenetic tree
Pseudomonas fluorescens