Carnobacterium, a genus of lactic acid bacteria, frequently dominate the microflora of chilled vacuum- or modified atmosphere-packed meat and seafood. In this study Carnobacterium isolates were characterized by phenotypic and molecular methods in order to investigate the association of species and intra-species groups with distinct kinds of meat and seafood. Of 120 test strains, 50 originated from meat (beef and pork products, including 44 strains isolated during this study and 6 strains obtained from culture collections) and 52 from seafoods (cod, halibut, salmon, shrimps and roe products). In addition, 9 reference strains of Carnobacterium spp from other sources than meat and fish and 9 reference strains of lactic acid bacteria belonging to other genera than Carnobacterium were included. Numerical taxonomy relying on classical biochemical reactions, carbohydrate fermentation and inhibition tests (temperature, salt, pH, chemical preservatives, antibiotics, bacteriocins), SDS-PAGE electrophoresis of whole cell proteins, plasmid profiling, intergenic spacer region (ISR) analysis and examination of amplified-fragment length polymorphism (AFLP) were employed to characterize the strains. The numerical taxonomic approach divided the carnobacteria strains into 24 groups that shared less than 89% similarity. These groups were identified as Carnobacterium divergens with one major cluster (40 strains) and 7 branches of one to four strains, Carnobacterium maltaromaticum (previous C. piscicola) with one major cluster (37 strains) and 9 branches of one to four strains and Carnobacterium mobile (three branches consisting in total of 4 strains). Branches consisting of references strains of the remaining Carnobacterium spp. were separated from clusters and branches of C. divergens, C. maltaromaticum and C. mobile. Isolates from the main clusters of C. divergens and C. maltaromaticum were found both in fresh and lightly preserved meat and seafood products. High phenotypic intra-species variability was observed for C. divergens and C. maltaromaticum but despite this heterogeneity in phenotypic traits a reliable identification to species levels was obtained by SDS-PAGE electrophoresis of whole cell proteins and by ISR based on 16S-23S rDNA intergenic spacer region polymorphism. With AFLP, two distinct clusters were observed for C. divergens but only one for C. maltaromaticum. The two C. divergens clusters were not identical to any of the clusters observed by numerical taxonomy. A limited number of C. divergens and C. maltaromaticum isolates possessed a biopreservative potential due to their production of bacteriocins with a wide inhibition spectrum. This study serves as a base-line for further investigations on the potential role of species of Carnobacterium in foods where they predominate the spoilage microflora.

中文翻译：

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肉食和海鲜中的变味嘉诺氏菌和麦芽糖诺氏菌作为破坏物或保护性培养物：表型和基因型特征。

食肉杆菌是乳酸菌的一种，通常在冷藏的真空或改良的常压包装的肉类和海鲜的微生物区系中占主导地位。在这项研究中，通过表型和分子方法对食肉杆菌分离株进行了表征，以研究物种和种内群与不同种类的肉和海鲜的关联。在120个测试菌株中，有50个来源于肉类（牛肉和猪肉制品，包括在本研究中分离出的44个菌株，以及从养殖收藏中获得的6个菌株），还有52个来自海鲜（鳕鱼，大比目鱼，鲑鱼，虾和鱼子制品）。另外，还包括来自肉和鱼以外的来源的食肉杆菌属的9种参考菌株和属于食肉杆菌属之外的其他属的乳酸菌的9种参考菌株。数值分类法依靠经典的生化反应，碳水化合物发酵和抑制试验（温度，盐，pH，化学防腐剂，抗生素，细菌素），全细胞蛋白的SDS-PAGE电泳，质粒图谱，基因间隔区（ISR）分析和检查扩增片段长度多态性（AFLP）被用来表征菌株。数值分类学方法将食肉杆菌菌株分为24组，其相似度低于89％。这些群体被鉴定为具有1个主要簇（40个菌株）和1至4个菌株的7个分支的多歧食弧菌，具有1个主要簇（37个菌株）和1至4个菌株的9个分支的麦芽糖食杆菌（以前的C. piscicola）和可移动的（三个分支，共4个菌株）。分支由剩余的肉芽孢杆菌属的参考菌株组成。从C. divergens，C。maltaromaticum和C. mobile的簇和分支中分离。在新鲜和轻度保存的肉类和海鲜产品中均发现了来自C. divergens和C. maltaromaticum的主要簇的分离物。观察到C. divergens和C. maltaromaticum的高表型种内变异性，但是尽管表型性状存在这种异质性，但通过全细胞蛋白的SDS-PAGE电泳和基于16S-23S rDNA基因间的ISR仍能可靠地鉴定物种水平间隔区多态性。用AFLP，对于C. divergens观察到两个不同的簇，但对于C. maltaromaticum仅观察到一个。这两个C. divergens聚类与通过数字分类法观察到的任何聚类都不相同。有限数量的C. divergens和C. maltaromaticum分离物由于具有宽抑制谱的细菌素产生而具有生物防腐潜力。这项研究为进一步研究食肉杆菌属在腐败菌群中占主导地位的食品的潜在作用提供了依据。