Park Kyung-Min, Kim Hyun-Jung, Kim Min-Sun, Koo Minseon
Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea.
Research Group of Consumer Safety, Korea Food Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea.
Microorganisms. 2021 Jun 9;9(6):1255. doi: 10.3390/microorganisms9061255.
At low temperatures, psychrotolerant group strains exhibit a higher growth rate than mesophilic strains do. However, the different survival responses of the psychrotolerant strain (BCG) and the mesophilic strain (BCG) at low temperatures are unclear. We investigated the morphological and genomic features of BCG and BCG to characterize their growth strategies at low temperatures. At low temperatures, morphological changes were observed only in BCG. These morphological changes included the elongation of rod-shaped cells, whereas the cell shape in BCG was unchanged at the low temperature. A transcriptomic analysis revealed that both species exhibited different growth-related traits during low-temperature growth. The BCG strain induces fatty acid biosynthesis, sulfur assimilation, and methionine and cysteine biosynthesis as a survival mechanism in cold systems. Increases in energy metabolism and fatty acid biosynthesis in the mesophilic group strain might explain its ability to grow at low temperatures. Several pathways involved in carbohydrate mechanisms were downregulated to conserve the energy required for growth. Peptidoglycan biosynthesis was upregulated, implying that a change of gene expression in both RNA-Seq and RT-qPCR contributed to sustaining its growth and rod shape at low temperatures. These results improve our understanding of the growth response of the group, including psychrotolerant group strains, at low temperatures and provide information for improving bacterial inhibition strategies in the food industry.
在低温下，耐冷菌群菌株的生长速率高于嗜温菌株。然而，耐冷菌株（BCG）和嗜温菌株（BCG）在低温下不同的存活反应尚不清楚。我们研究了BCG和BCG的形态和基因组特征，以表征它们在低温下的生长策略。在低温下，仅在BCG中观察到形态变化。这些形态变化包括杆状细胞的伸长，而BCG中的细胞形状在低温下未发生变化。转录组分析表明，两种菌株在低温生长过程中表现出不同的与生长相关的特征。BCG菌株诱导脂肪酸生物合成、硫同化以及蛋氨酸和半胱氨酸生物合成，作为在寒冷系统中的一种生存机制。嗜温菌群菌株中能量代谢和脂肪酸生物合成的增加可能解释了其在低温下生长的能力。参与碳水化合物机制的几种途径被下调，以保存生长所需的能量。肽聚糖生物合成上调，这意味着RNA测序和逆转录定量聚合酶链反应中的基因表达变化有助于其在低温下维持生长和杆状形态。这些结果增进了我们对包括耐冷菌群菌株在内的菌群在低温下生长反应的理解，并为改进食品工业中的细菌抑制策略提供了信息。
