Organisms display an immense variety of shapes, sizes, and reproductive strategies. At microscopic scales, bacterial cell morphology and growth dynamics are adaptive traits that influence the spatial organization of microbial communities. In one such community—the human dental plaque biofilm—a network of filamentous Corynebacterium matruchotii cells forms the core of bacterial consortia known as hedgehogs, but the processes that generate these structures are unclear. Here, using live-cell time-lapse microscopy and fluorescent D-amino acids to track peptidoglycan biosynthesis, we report an extraordinary example of simultaneous multiple division within the domain Bacteria . We show that C. matruchotii cells elongate at one pole through tip extension, similar to the growth strategy of soil-dwelling Streptomyces bacteria. Filaments elongate rapidly, at rates more than five times greater than other closely related bacterial species. Following elongation, many septa form simultaneously, and each cell divides into 3 to 14 daughter cells, depending on the length of the mother filament. The daughter cells then nucleate outgrowth of new thinner vegetative filaments, generating the classic “whip handle” morphology of this taxon. Our results expand the known diversity of bacterial cell cycles and help explain how this filamentous bacterium can compete for space, access nutrients, and form important interspecies interactions within dental plaque.

中文翻译：

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丝状细菌的尖端延伸和同时多重裂变


生物体表现出多种多样的形状、大小和繁殖策略。在微观尺度上，细菌细胞形态和生长动力学是影响微生物群落空间组织的适应性特征。在这样一个群落中——人类牙菌斑生物膜——丝状棒状杆菌细胞网络形成了被称为“刺猬”的细菌群落的核心，但产生这些结构的过程尚不清楚。在这里，我们使用活细胞延时显微镜和荧光 D-氨基酸来追踪肽聚糖生物合成，报告了细菌领域内同时多重分裂的一个非凡例子。我们发现 C. matruchotii 细胞通过尖端延伸在一极伸长，类似于土壤中链霉菌的生长策略。细丝伸长迅速，其伸长速度是其他密切相关的细菌物种的五倍以上。伸长后，许多隔膜同时形成，每个细胞分裂成 3 至 14 个子细胞，具体取决于母丝的长度。然后，子细胞核生长出新的更细的营养丝，形成该分类群的经典“鞭柄”形态。我们的研究结果扩展了细菌细胞周期的已知多样性，并有助于解释这种丝状细菌如何竞争空间、获取营养并在牙菌斑内形成重要的种间相互作用。