Salvador Maika, Condón Santiago, Gayán Elisa
Department of Animal Production and Food Science, Faculty of Veterinary, AgriFood Institute of Aragon (IA2), University of Zaragoza-CITA, Miguel Servet 177, 50013 Zaragoza, Spain.
Foods. 2025 Jun 11;14(12):2061. doi: 10.3390/foods14122061.
and spores are major spoilage agents in thermally treated, shelf-stable foods, particularly milk products, due to their high heat resistance. This study aimed to investigate how spore purification, maturation time, and sporulation temperature influence the germination and heat resistance of , , and spores, with the goal of improving the reliability of microbial risk assessment. All three species germinate efficiently in milk, likely triggered by lactose and glucose. Ethanol-treated spores during purification germinated without heat activation, while water-washed spores required it. At least four days of maturation were needed for efficient germination, though extending maturation to seven days led to strain-dependent changes in heat resistance: it increased in , decreased in , and remained stable in . Sporulation at 55 °C consistently favored germination at the same revival temperature. reached the highest heat resistance at 55 °C, whereas the other species were more resistant when sporulated at 60 °C. These findings underscore the importance of standardizing spore-preparation protocols, as key parameters such as purification, maturation time, and sporulation temperature critically affect spore properties relevant to food stability.
由于其高耐热性，芽孢杆菌属芽孢是热处理货架稳定食品（特别是乳制品）中的主要腐败因子。本研究旨在调查芽孢纯化、成熟时间和芽孢形成温度如何影响嗜热栖热菌、嗜热栖热菌和嗜热栖热菌芽孢的萌发和耐热性，以提高微生物风险评估的可靠性。这三个物种在牛奶中均能高效萌发，可能是由乳糖和葡萄糖触发的。纯化过程中经乙醇处理的芽孢无需热激活即可萌发，而水洗芽孢则需要热激活。高效萌发至少需要四天的成熟时间，不过将成熟时间延长至七天会导致不同菌株的耐热性发生变化：嗜热栖热菌的耐热性增加，嗜热栖热菌的耐热性降低，嗜热栖热菌的耐热性保持稳定。在55°C下进行芽孢形成始终有利于在相同复苏温度下的萌发。嗜热栖热菌在55°C时达到最高耐热性，而其他物种在60°C下进行芽孢形成时更具抗性。这些发现强调了标准化芽孢制备方案的重要性，因为纯化、成熟时间和芽孢形成温度等关键参数会严重影响与食品稳定性相关的芽孢特性。
