Suo Biao, Guan Peng, Dong Zijie, Zeng Yun, Fan Shijia, Fan Huiping, Huang Zhongmin, Ai Zhilu
College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, China.
Key Laboratory of Staple Grain Processing, Ministry of Agriculture and Rural Affairs, Zhengzhou 450002, China.
Foods. 2022 Mar 29;11(7):996. doi: 10.3390/foods11070996.
In food processing, the temperature is usually reduced to limit bacterial reproduction and maintain food safety. However, can adapt to low temperatures by controlling gene expression and protein activity, although its survival strategies normally vary between different strains. The present study investigated the molecular mechanisms of with different survival strategies in response to low temperatures (4 °C). The survival curve showed that strain BA-26 was inactivated by 6.0 logCFU/mL after 4 weeks of low-temperature treatment, while strain BB-11 only decreased by 1.8 logCFU/mL. Intracellular nucleic acid leakage, transmission electron microscopy, and confocal laser scanning microscopy analyses revealed better cell membrane integrity of strain BB-11 than that of strain BA-26 after low-temperature treatment. Regarding oxidative stress, the superoxide dismutase activity and the reduced glutathione content in BB-11 were higher than those in BA-26; thus, BB-11 contained less malondialdehyde than BA-26. RNA-seq showed a significantly upregulated expression of the fatty acid biosynthesis in membrane gene () in BB-11 compared with BA-26 because of the damaged cell membrane. Then, catalase (), reduced glutathione (), and peroxidase () were found to be significantly upregulated in BB-11, leading to an increase in the oxidative stress response, but BA-26-related genes were downregulated. NADH dehydrogenase () and α-glucosidase () were upregulated in the cold-tolerant strain BB-11 but were downregulated in the cold-sensitive strain BA-26, suggesting that energy metabolism might play a role in under low-temperature stress. Furthermore, defense mechanisms, such as those involving , and played a pivotal role in the response of BB-11 to stress. The study provided a new perspective for understanding the survival mechanism of at low temperatures.
在食品加工过程中，通常会降低温度以限制细菌繁殖并维持食品安全。然而，（此处原文有缺失信息，推测是某种细菌）可以通过控制基因表达和蛋白质活性来适应低温，尽管其生存策略通常因不同菌株而异。本研究调查了具有不同生存策略的（推测的细菌）在低温（4℃）下的分子机制。生存曲线表明，低温处理4周后，BA - 26菌株的灭活量为6.0 logCFU/mL，而BB - 11菌株仅下降了1.8 logCFU/mL。细胞内核酸泄漏、透射电子显微镜和共聚焦激光扫描显微镜分析显示，低温处理后，BB - 11菌株的细胞膜完整性优于BA - 26菌株。关于氧化应激，BB - 11中的超氧化物歧化酶活性和还原型谷胱甘肽含量高于BA - 26；因此，BB - 11中的丙二醛含量低于BA - 26。RNA测序显示，与BA - 26相比，BB - 11中膜基因（此处原文有缺失信息，推测是某个与脂肪酸生物合成相关的膜基因）的脂肪酸生物合成表达显著上调，这是由于细胞膜受损所致。然后，发现BB - 11中的过氧化氢酶（此处原文有缺失信息，推测是某个酶的名称）、还原型谷胱甘肽（此处原文有缺失信息，推测是某个物质的名称）和过氧化物酶（此处原文有缺失信息，推测是某个酶的名称）显著上调，导致氧化应激反应增加，但BA - 26相关基因下调。耐冷菌株BB - 11中的NADH脱氢酶（此处原文有缺失信息，推测是某个酶的名称）和α - 葡萄糖苷酶（此处原文有缺失信息，推测是某个酶的名称）上调，而冷敏感菌株BA - 26中的这些酶下调，这表明能量代谢可能在低温胁迫下的（推测的细菌）中发挥作用。此外，诸如涉及（此处原文有缺失信息，推测是某些物质或机制的名称）、（此处原文有缺失信息，推测是某些物质或机制的名称）和（此处原文有缺失信息，推测是某些物质或机制的名称）的防御机制在BB - 11对胁迫的反应中起关键作用。该研究为理解（推测的细菌）在低温下的生存机制提供了新的视角。
