Department of Food Science and Technology, Faculty of Veterinary, Agrifood Campus of International Excellence (ceiA3), University of Cordoba, 14014, Córdoba, Spain.
Department of Food Science and Technology, Faculty of Veterinary, Agrifood Campus of International Excellence (ceiA3), University of Cordoba, 14014, Córdoba, Spain.
Food Microbiol. 2021 Apr;94:103649. doi: 10.1016/j.fm.2020.103649. Epub 2020 Sep 30.
In this study, the bioprotective potential of Lactobacillus sakei CTC494 against Listeria monocytogenes CTC1034 was evaluated on vacuum packaged hot-smoked sea bream at 5 °C and dynamic temperatures ranging from 3 to 12 °C. The capacity of three microbial competition interaction models to describe the inhibitory effect of L. sakei CTC494 on L. monocytogenes was assessed based on the Jameson effect and Lotka-Volterra approaches. A sensory analysis was performed to evaluate the spoiling capacity of L. sakei CTC494 on the smoked fish product at 5 °C. Based on the sensory results, the bioprotection strategy against the pathogen was established by inoculating the product at a 1:2 ratio (pathogen:bioprotector, log CFU/g). The kinetic growth parameters of both microorganisms were estimated in mono-culture at constant storage (5 °C). In addition, the inhibition function parameters of the tested interaction models were estimated in co-culture at constant and dynamic temperature storage using as input the mono-culture kinetic parameters. The growth potential (δ log) of L. monocytogenes, in mono-culture, was 3.5 log on smoked sea bream during the experimental period (20 days). In co-culture, L. sakei CTC494 significantly reduced the capability of L. monocytogenes to grow, although its effectiveness was temperature dependent. The LAB strain limited the growth of the pathogen under storage at 5 °C (<1 log increase) and at dynamic profile 2 (<2 log increase). Besides, under storage at dynamic profile 1, the growth of L. monocytogenes was inhibited (<0.5 log increase). These results confirmed the efficacy of L. sakei CTC494 for controlling the pathogen growth on the studied fish product. The Lotka-Volterra competition model showed slightly better fit to the observed L. monocytogenes growth response than the Jameson-based models according to the statistical performance. The proposed modelling approach could support the assessment and establishment of bioprotective culture-based strategies aimed at reducing the risk of listeriosis linked to the consumption of RTE hot-smoked sea bream.
在这项研究中，评估了乳杆菌 CTC494 对单增李斯特菌 CTC1034 在 5°C 下真空包装的热熏海鲈以及 3 至 12°C 动态温度下的生物保护潜力。基于 Jameson 效应和 Lotka-Volterra 方法，评估了三种微生物竞争相互作用模型描述乳杆菌 CTC494 对单增李斯特菌抑制作用的能力。进行了感官分析，以评估乳杆菌 CTC494 在 5°C 下对熏制鱼产品的腐败能力。根据感官结果，通过以 1:2 的比例（病原体：生物保护剂，log CFU/g）接种产品，建立了针对病原体的生物保护策略。在恒温（5°C）下进行单培养时，估计了两种微生物的动力学生长参数。此外，使用单培养动力学参数作为输入，在恒温和动态温度下的共培养中估计了测试相互作用模型的抑制功能参数。单培养中，李斯特菌的生长潜力（δ log）在实验期间（20 天）在熏制海鲈上为 3.5 log。在共培养中，乳杆菌 CTC494 显著降低了单增李斯特菌的生长能力，尽管其效果取决于温度。在 5°C 下（<1 log 增加）和动态剖面 2 下（<2 log 增加），LAB 菌株限制了病原体的生长。此外，在动态剖面 1 下，单增李斯特菌的生长受到抑制（<0.5 log 增加）。这些结果证实了乳杆菌 CTC494 控制研究鱼产品中病原体生长的功效。根据统计性能，Lotka-Volterra 竞争模型对单增李斯特菌生长反应的拟合效果略优于基于 Jameson 的模型。所提出的建模方法可以支持评估和建立基于生物保护的文化策略，以降低与消费即食热熏海鲈相关的李斯特菌病风险。
