Genomic insights into the alphaproteobacterium <i>Georhizobium</i> sp. MAB10 revealed a pathway of Mn(II) oxidation-coupled anoxygenic photoautotrophy: a novel understanding of the biotic process in deep-sea ferromanganese nodule formation

Microorganisms are believed to participate in the biotic process of deep-sea ferromanganese nodule formation [Mn(II) oxidation]. Despite the multitude of studies and reviews focusing on the details of Mn(II) oxidation catalyzed by diverse heterotrophs, the mechanistic roles of manganese chemolithotrophs from ferromanganese nodules remain unclear. We demonstrate that strain <i>Georhizobium</i> sp. MAB10 can utilize Mn(II)-derived electrons for photoautotrophic growth, with concomitant generation of dark β-MnO₂ type Mn oxides under near-infrared light condition. This study uses genomic and biochemical assays to explore the genetic basis of Mn(II) oxidation-coupled anoxygenic photoautotrophy. The comprehensive analyses of respiration and carbon and nitrogen metabolism further elucidated the high ecophysiological flexibility of strain MAB10 in deep-sea habits. These findings expand our understanding of the role of chemolithotrophs in deep-sea ferromanganese nodule formation and justify further investigations into the molecular basis for Mn(II) oxidation-coupled anoxygenic photoautotrophy.