Suzina Nataliya E, Sorokin Vladimir V, Polivtseva Valentina N, Klyueva Violetta V, Emelyanova Elena V, Solyanikova Inna P
Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute of Biochemistry and Physiology of Microorganisms, 142290 Pushchino, Russia.
Federal Research Center of Biotechnology of the Russian Academy of Sciences, Winogradsky Institute of Microbiology, 117312 Moscow, Russia.
Microorganisms. 2022 Feb 18;10(2):465. doi: 10.3390/microorganisms10020465.
In the process of evolution, living organisms develop mechanisms for population preservation to survive in unfavorable conditions. Spores and cysts are the most obvious examples of dormant forms in microorganisms. Non-spore-forming bacteria are also capable of surviving in unfavorable conditions, but the patterns of their behavior and adaptive reactions have been studied in less detail compared to spore-forming organisms. The purpose of this work was to study the features of transition from dormancy to active vegetative growth in one of the non-spore-forming bacteria, 135, which is known as a destructor of such aromatic compounds as benzoate, 3-chlorobenzoate, and phenol. It was shown that 135 under unfavorable conditions forms cyst-like cells with increased thermal resistance. Storage for two years does not lead to complete cell death. When the cells were transferred to fresh nutrient medium, visible growth was observed after 3 h. Immobilized cells stored at 4 °C for at least 10 months regenerated their metabolic activity after only 30 min of aeration. A study of the ultrathin organization of resting cells by transmission electron microscopy combined with X-ray microanalysis revealed intracytoplasmic electron-dense spherical membrane ultrastructures with significant similarity to previously described acidocalcisomas. The ability of some resting 135 cells in the population to secrete acidocalcisome-like ultrastructures into the extracellular space was also detected. These structures contain predominantly calcium (Ca) and, to a lesser extent, phosphorus (P), and are likely to serve as depots of vital macronutrients to maintain cell viability during resting and provide a quick transition to a metabolically active state under favorable conditions. The study revealed the features of transitions from active growth to dormant state and vice versa of non-spore-forming bacteria 135 and the possibility to use them as the basis of biopreparations with a long shelf life.
在进化过程中，生物体会形成种群保存机制，以便在不利条件下生存。孢子和孢囊是微生物中休眠形式最明显的例子。非芽孢形成细菌也能够在不利条件下存活，但与芽孢形成生物体相比，它们的行为模式和适应性反应的研究还不够详细。这项工作的目的是研究一种非芽孢形成细菌135从休眠状态转变为活跃营养生长的特征，该细菌是苯甲酸、3-氯苯甲酸和苯酚等芳香族化合物的分解者。结果表明，135在不利条件下会形成热抗性增强的囊状细胞。储存两年不会导致细胞完全死亡。当将细胞转移到新鲜营养培养基中时，3小时后观察到明显的生长。固定化细胞在4℃下储存至少10个月，仅通气30分钟后就恢复了代谢活性。通过透射电子显微镜结合X射线微分析对静止细胞的超薄结构进行研究，发现胞质内有电子致密的球形膜超结构，与先前描述的酸性钙小体有显著相似性。还检测到群体中一些静止的135细胞有能力将类似酸性钙小体的超结构分泌到细胞外空间。这些结构主要含有钙（Ca），其次含有磷（P），可能作为重要常量营养素的储存库，以在静止期间维持细胞活力，并在有利条件下快速转变为代谢活跃状态。该研究揭示了非芽孢形成细菌135从活跃生长到休眠状态以及反之亦然的转变特征，以及将它们用作具有长保质期的生物制剂基础的可能性。
