Abstract：
OBJECTIVE: This study aimed to prospect and isolate lactic acid bacteria (LAB) from an artisanal cheese production environment, to assess their safety, and to explore their bacteriocinogenic potential against Listeria monocytogenes.
RESULTS: Samples were collected from surfaces of an artisanal-cheese production facility and after rep-PCR and 16S rRNA sequencing analysis, selected strains were identified as to be belonging to Lactococcus garvieae (1 strain) and Enterococcus faecium (14 isolates, grouped into three clusters) associated with different environments (worktables, cheese mold, ripening wooden shelves). All of them presented bacteriocinogenic potential against L. monocytogenes ATCC 7644 and were confirmed as safe (γ-hemolytic, not presenting antibiotic resistance, no mucus degradation properties, and no proteolytic or gelatinase enzyme activity). Additionally, cell growth, acidification and bacteriocins production kinetics, bacteriocin stability in relation to different temperatures, pH, and chemicals were evaluated. According to performed PCR analysis all studied strains generated positive evidence for the presence of entA and entP genes (for production of enterocins A and enterocins P, respectively). However, pediocin PA-1 associated gene was recorded only in DNA obtained from E. faecium ST02JL and Lc. garvieae ST04JL.
CONCLUSIONS: It is worth considering the application of these safe LAB or their bacteriocins in situ as an alternative means of controlling L. monocytogenes in cheese production environments, either alone or in combination with other antimicrobials.
RESULTS: Samples were collected from surfaces of an artisanal-cheese production facility and after rep-PCR and 16S rRNA sequencing analysis, selected strains were identified as to be belonging to Lactococcus garvieae (1 strain) and Enterococcus faecium (14 isolates, grouped into three clusters) associated with different environments (worktables, cheese mold, ripening wooden shelves). All of them presented bacteriocinogenic potential against L. monocytogenes ATCC 7644 and were confirmed as safe (γ-hemolytic, not presenting antibiotic resistance, no mucus degradation properties, and no proteolytic or gelatinase enzyme activity). Additionally, cell growth, acidification and bacteriocins production kinetics, bacteriocin stability in relation to different temperatures, pH, and chemicals were evaluated. According to performed PCR analysis all studied strains generated positive evidence for the presence of entA and entP genes (for production of enterocins A and enterocins P, respectively). However, pediocin PA-1 associated gene was recorded only in DNA obtained from E. faecium ST02JL and Lc. garvieae ST04JL.
CONCLUSIONS: It is worth considering the application of these safe LAB or their bacteriocins in situ as an alternative means of controlling L. monocytogenes in cheese production environments, either alone or in combination with other antimicrobials.
摘要：
目的：本研究旨在从手工奶酪生产环境中展望和分离LAB，为了评估他们的安全，并探索它们对单核细胞增生李斯特菌的细菌致病潜力。
结果：从手工奶酪生产设施的表面收集样品，并经过rep-PCR和16SrRNA测序分析，所选菌株被鉴定为属于链球菌（1株）和屎肠球菌（14株，分为3个集群)与不同的环境(工作表，奶酪模具，成熟的木制架子)。所有这些都具有针对单核细胞增生李斯特菌ATCC7644的细菌产生潜力，并被证实是安全的（γ-溶血，不存在抗生素耐药性，无粘液降解特性，无蛋白水解或明胶酶活性）。此外,细胞生长,酸化和细菌素生产动力学，细菌素相对于不同温度的稳定性，评估pH和化学品。根据进行的PCR，所有研究的菌株都产生了entA和entP基因存在的阳性证据（用于生产肠菌素A和肠菌素P，分别)。然而,仅记录了来自屎肠球菌ST02JL和Lc的pediacinPA-1相关基因。garvieaeST04JL.
结论：值得考虑将这些安全的LAB或其细菌素原位应用为单独或与其他抗菌剂组合在奶酪生产环境中控制单核细胞增生李斯特菌的替代手段。
结果：从手工奶酪生产设施的表面收集样品，并经过rep-PCR和16SrRNA测序分析，所选菌株被鉴定为属于链球菌（1株）和屎肠球菌（14株，分为3个集群)与不同的环境(工作表，奶酪模具，成熟的木制架子)。所有这些都具有针对单核细胞增生李斯特菌ATCC7644的细菌产生潜力，并被证实是安全的（γ-溶血，不存在抗生素耐药性，无粘液降解特性，无蛋白水解或明胶酶活性）。此外,细胞生长,酸化和细菌素生产动力学，细菌素相对于不同温度的稳定性，评估pH和化学品。根据进行的PCR，所有研究的菌株都产生了entA和entP基因存在的阳性证据（用于生产肠菌素A和肠菌素P，分别)。然而,仅记录了来自屎肠球菌ST02JL和Lc的pediacinPA-1相关基因。garvieaeST04JL.
结论：值得考虑将这些安全的LAB或其细菌素原位应用为单独或与其他抗菌剂组合在奶酪生产环境中控制单核细胞增生李斯特菌的替代手段。
