为研究冷却猪肉及其接触面中细菌生物被膜能力并探讨肉类特定腐败菌的生物被膜特征，分析了腐败的冷却肉和销售托盘表面的细菌生物被膜形成能力；利用形态学观察、16S rDNA分析和VITEK2微生物鉴定系统鉴定了冷却肉中一株生物被膜能力较强的荧光假单胞菌（Pseudomonas fluorescens）；测定了该菌在培养基和猪肉浸提液中的生物被膜能力；用激光共聚焦和扫描电子显微镜观测了其生物被膜的结构特征。结果发现：冷却肉中及其销售托盘表面的细菌能够形成生物被膜的比例较高，37%和45%的细菌具有较强生物被膜形成能力。肉源性荧光假单胞菌能够在培养基和肉液中形成大量生物被膜，具有较强的生物被膜能力。显微成像结果表明荧光假单胞菌在培养6 h后有明显黏附，18 h后多糖分泌增多、菌体堆积并形成具有生物功能的立体生物被膜。这些特点可能有利于荧光假单胞菌在冷却肉表面黏附并成为优势腐败菌。

To study the biofilm risk and the biofilm characteristics of meat-related spoilage bacteria in chilled pork and on tray surface, the biofilm formation ability of bacteria in chilled pork and on tray surface were analyzed, and one strain that have strong capability to form biofilm was identified as Pseudomonas fluorescens by morphological observation, 16S rDNA sequence analysis and VITEK2 microbial identification system. The biofilm formation ability of this meat-related specific spoilage bacterium was measured in tryptic soy broth and pork extraction. Additionally, the biological structure of its biofilms during development was visualized using confocal laser scanning microscopy and scanning electron microscope. A high percentage of the bacteria in chilled pork and on tray surface was able to form biofilms, 37% bacteria from chilled pork and 45% bacteria from tray surface formed biofilm strongly. The Pseudomonas fluorescens was quite capable to form biofilm in both TSB culture and pork extraction. It showed a significantly adhesion ability after cultured for 6 hours, expressed more polysaccharides and formed biological three-dimensional function structures after 18 hours. These features may be beneficial for the meat-related Pseudomonas fluorescens to adhere to chilled meat surface and become the dominant spoilage bacteria.

国家“十二五”支撑计划课题（2013BAD19B06）