Xu Xiuli, Zhang Litao, Song Fuhang, Zhang Guoliang, Ma Linlin, Yang Na
Key Laboratory of Polar Geology and Marine Mineral Resources (China University of Geosciences, Beijing), Ministry of Education; Hainan Institute of China University of Geosciences (Beijing); School of Ocean Sciences, China University of Geosciences, Beijing, P. R. China.
CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, P. R. China.
mBio. 2025 Jan 8;16(1):e0267524. doi: 10.1128/mbio.02675-24. Epub 2024 Nov 25.
Under light conditions, Mn(II) facilitates the photoautotrophic growth of sp. MAB10, a strain derived from deep-sea ferromanganese nodules, along with the generation of dark Mn oxides (β-MnO). This study investigated the genetic basis of Mn(II) oxidation-coupled anoxygenic photoautotrophy using genome sequencing and biochemical assays of strain MAB10. Preliminary results indicated the presence of genes encoding a functional pheophytin-quinone-type photosynthetic reaction center and a putative key enzyme for Mn(II) oxidation, namely FtsP/CotA-like multicopper oxidase GE001273. Under light conditions, Mn(II) significantly reduced the respiration rate and elevated the intracellular NADH/NAD ratio. This suggested that Mn(II)-derived electrons entered the cyclic photophosphorylation, partially replacing the oxidative phosphorylation for ATP production and enhancing the electron flow to complex I for NADH generation. enzymatic studies confirmed that GE001273 was a catalyst for Mn(II) oxidation in the outer membrane. Comprehensive genomic analyses of respiration and carbon and nitrogen metabolism revealed the high ecophysiological flexibility of strain MAB10 during Mn(II) oxidation-coupled anoxygenic photoautotrophy in deep-sea habitats. These analyses provided insights into bacterial Mn(II) oxidation-coupled anoxygenic photoautotrophy during microorganism-mediated 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 sp. MAB10 can utilize Mn(II)-derived electrons for photoautotrophic growth, with concomitant generation of dark β-MnO 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.
在光照条件下，锰（II）促进了源自深海铁锰结核的菌株MAB10的光合自养生长，并伴随着暗锰氧化物（β - 二氧化锰）的生成。本研究使用菌株MAB10的基因组测序和生化分析，探究了锰（II）氧化耦合的无氧光合自养的遗传基础。初步结果表明存在编码功能性脱镁叶绿素 - 醌型光合反应中心的基因，以及一种推测的锰（II）氧化关键酶，即FtsP/CotA样多铜氧化酶GE001273。在光照条件下，锰（II）显著降低了呼吸速率，并提高了细胞内NADH/NAD比率。这表明锰（II）衍生的电子进入循环光合磷酸化，部分替代氧化磷酸化来产生ATP，并增强电子流向复合物I以生成NADH。酶学研究证实GE001273是外膜中锰（II）氧化的催化剂。对呼吸以及碳和氮代谢的综合基因组分析揭示了菌株MAB10在深海栖息地锰（II）氧化耦合的无氧光合自养过程中的高生态生理灵活性。这些分析为微生物介导的深海铁锰结核形成过程中细菌的锰（II）氧化耦合的无氧光合自养提供了见解。
微生物被认为参与深海铁锰结核形成的生物过程（锰（II）氧化）。尽管有众多研究和综述聚焦于各种异养菌催化的锰（II）氧化细节，但来自铁锰结核的锰化能自养菌的机制作用仍不清楚。我们证明菌株MAB10可以利用锰（II）衍生的电子进行光合自养生长，并在近红外光条件下伴随着暗β - 二氧化锰型锰氧化物的生成。本研究使用基因组和生化分析来探索锰（II）氧化耦合的无氧光合自养的遗传基础。对呼吸以及碳和氮代谢的综合分析进一步阐明了菌株MAB10在深海环境中的高生态生理灵活性。这些发现扩展了我们对化能自养菌在深海铁锰结核形成中作用的理解，并为进一步研究锰（II）氧化耦合的无氧光合自养的分子基础提供了依据。
