Candeliere Francesco, Raimondi Stefano, Spampinato Gloria, Tay Moon Yue Feng, Amaretti Alberto, Schlundt Joergen, Rossi Maddalena
Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
Nanyang Technological University Food Technology Centre (NAFTEC), Singapore, Singapore.
Front Microbiol. 2021 Jan 11;11:605127. doi: 10.3389/fmicb.2020.605127. eCollection 2020.
is a known colonizer of meat-related food matrices. It reaches remarkably high loads during the shelf life in packaged meat products and plays a role in spoilage, although preservative effects have been proposed for some strains. In this study, the draft genomes of 17 strains of (i.e., all the strains that have been sequenced so far) were compared to decipher their metabolic and functional potential and to determine their role in food transformations. Genome comparison and pathway reconstruction indicated that m is a compact group of closely related heterofermentative bacteria sharing most of the metabolic features. Adaptation to a nitrogen-rich environment, such as meat, is evidenced by 23 peptidase genes identified in the core genome and by the autotrophy for nitrogen compounds including several amino acids, vitamins, and cofactors. Genes encoding the decarboxylases yielding biogenic amines were not present. All the strains harbored 1-4 of 32 different plasmids, bearing functions associated to proteins hydrolysis, transport of amino acids and oligopeptides, exopolysaccharides, and various resistances (e.g., to environmental stresses, bacteriophages, and heavy metals). Functions associated to bacteriocin synthesis, secretion, and immunity were also found in plasmids. While genes for lactococcin were found in most plasmids, only three harbored the genes for leucocin B, a class IIa antilisterial bacteriocin. Determinants of antibiotic resistances were absent in both plasmids and chromosomes.
是与肉类相关食品基质的已知定植菌。在包装肉类产品的保质期内，它能达到非常高的数量，并在腐败过程中起作用，尽管已提出某些菌株具有防腐作用。在本研究中，对17株（即迄今为止已测序的所有菌株）的基因组草图进行了比较，以解读它们的代谢和功能潜力，并确定它们在食品转化中的作用。基因组比较和途径重建表明，是一组紧密相关的异源发酵细菌，具有大部分代谢特征。核心基因组中鉴定出的23个肽酶基因以及包括几种氨基酸、维生素和辅因子在内的氮化合物自养能力，证明了其对富含氮的环境（如肉类）的适应性。不存在编码产生生物胺的脱羧酶的基因。所有菌株都含有32种不同质粒中的1 - 4种，这些质粒具有与蛋白质水解、氨基酸和寡肽运输、胞外多糖以及各种抗性（如对环境压力、噬菌体和重金属的抗性）相关的功能。与细菌素合成、分泌和免疫相关的功能也在质粒中发现。虽然在大多数质粒中发现了乳球菌素基因，但只有三个质粒含有IIa类抗李斯特菌细菌素leucocin B的基因。质粒和染色体中均不存在抗生素抗性决定因素。
