Photosynthesis is a fundamental biogeochemical process, thought to be restricted to a few bacterial and eukaryotic phyla. However, understanding the origin and evolution of phototrophic organisms can be impeded and biased by the difficulties of cultivation. Here, we analyzed metagenomic datasets and found potential photosynthetic abilities encoded in the genomes of uncultivated bacteria within the phylum Myxococcota. A putative photosynthesis gene cluster encoding a type-II reaction center appears in at least six Myxococcota families from three classes, suggesting vertical inheritance of these genes from an early common ancestor, with multiple independent losses in other lineages. Analysis of metatranscriptomic datasets indicate that the putative myxococcotal photosynthesis genes are actively expressed in various natural environments. Furthermore, heterologous expression of myxococcotal pigment biosynthesis genes in a purple bacterium supports that the genes can drive photosynthetic processes. Given that predatory abilities are thought to be widespread across Myxococcota, our results suggest the intriguing possibility of a chimeric lifestyle (combining predatory and photosynthetic abilities) in members of this phylum.

光合作用是一个基本的生物地球化学过程，被认为仅限于少数细菌和真核生物门。然而，对光养生物的起源和进化的理解可能会因培养困难而受到阻碍和偏差。在这里，我们分析了宏基因组数据集，发现了粘球菌门内未培养细菌基因组中编码的潜在光合作用能力。编码 II 型反应中心的假定光合作用基因簇出现在来自三个纲的至少六个粘球菌科中，表明这些基因来自早期共同祖先的垂直遗传，而在其他谱系中存在多个独立的损失。宏转录组数据集的分析表明，假定的粘球菌光合作用基因在各种自然环境中活跃表达。此外，紫色细菌中粘球菌色素生物合成基因的异源表达支持该基因可以驱动光合作用过程。鉴于捕食能力被认为在粘球菌门中广泛存在，我们的研究结果表明该门成员存在嵌合生活方式（结合捕食能力和光合作用能力）的有趣可能性。