Tailocins are phage tail-like bacteriocins produced by various bacterial species to kill kin competitors. Given that tailocin release is dependent upon cell lysis, regulation of tailocin production at the single-cell and population level remains unclear. Here we used flow cytometry, competition assays and structural characterization of tailocin production in a human bacterial pathogen, Listeria monocytogenes. We revealed that a specialized subpopulation, constituting less than 1% of the total bacterial population, differentiates to produce, assemble and store thousands of tailocin particles. Tailocins are packed in a highly ordered manner, clustered in a liquid crystalline phase that occupies a substantial volume of the cell. Tailocin production confers a competitive growth advantage for the rest of the population. This study provides molecular insights into tailocin production as a form of altruism, showing how cell specialization within bacterial populations can confer competitive advantages at the population level.

Tailocins 是由各种细菌物种产生的噬菌体尾巴状细菌素，用于杀死亲属竞争者。鉴于 tailocin 的释放取决于细胞裂解，因此在单细胞和群体水平上对 tailocin 产生的调节仍不清楚。在这里，我们使用了流式细胞术、竞争测定和人类细菌病原体单核细胞增生李斯特菌中 tailocin 产生的结构表征。我们揭示了一个占细菌总种群不到 1% 的特殊亚群分化以产生、组装和储存数千个 tailocin 颗粒。Tailocin 以高度有序的方式包装，聚集在占据细胞大量体积的液晶相中。Tailocin 的生产为其他人群带来了有竞争力的增长优势。这项研究提供了对 tailocin 产生作为利他主义形式的分子见解，展示了细菌种群中的细胞特化如何在种群水平上赋予竞争优势。