White Isaac S, Canniffe Daniel P, Hitchcock Andrew
Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Liverpool, United Kingdom.
Plants, Photosynthesis and Soil, School of Biosciences, The University of Sheffield, Sheffield, United Kingdom; Molecular Microbiology - Biochemistry and Disease, School of Biosciences, The University of Sheffield, Sheffield, United Kingdom.
Adv Microb Physiol. 2025;86:1-98. doi: 10.1016/bs.ampbs.2025.02.003. Epub 2025 May 12.
Photosynthesis by (bacterio)chlorophyll-producing organisms ("chlorophototrophy") sustains virtually all life on Earth, providing the biosphere with food and energy. The oxygenic process carried out by plants, algae and cyanobacteria also generates the oxygen we breathe, and ancient cyanobacteria were responsible for oxygenating the atmosphere, creating the conditions that allowed the evolution of complex life. Cyanobacteria were also the endosymbiotic progenitors of chloroplasts, play major roles in biogeochemical cycles and as primary producers in aquatic ecosystems, and act as genetically tractable model organisms for studying oxygenic photosynthesis. In addition to the Cyanobacteriota, eight other bacterial phyla, namely Proteobacteria/Pseudomonadota, Chlorobiota, Chloroflexota, Bacillota, Acidobacteriota, Gemmatimonadota, Vulcanimicrobiota and Myxococcota contain at least one putative chlorophototrophic species, all of which perform a variant of anoxygenic photosynthesis, which does not yield oxygen as a by-product. These chlorophototrophic organisms display incredible diversity in the habitats that they colonise, and in their biochemistry, physiology and metabolism, with variation in the light-harvesting complexes and pigments they produce to utilise solar energy. Whilst some are very well understood, such as the proteobacterial 'purple bacteria', others have only been identified in the last few years and therefore relatively little is known about them - especially those that have not yet been isolated and cultured. In this chapter, we aim to summarise and compare the photosynthetic physiology and central metabolic processes of chlorophototrophic members from the nine phyla in which they are found, giving both a short historical perspective and highlighting gaps in our understanding.
通过产生（细菌）叶绿素的生物体进行的光合作用（“叶绿素光养作用”）维持了地球上几乎所有的生命，为生物圈提供食物和能量。植物、藻类和蓝细菌进行的产氧过程还产生了我们呼吸的氧气，古代蓝细菌负责使大气氧化，创造了使复杂生命得以进化的条件。蓝细菌也是叶绿体的内共生祖先，在生物地球化学循环中发挥主要作用，是水生生态系统中的初级生产者，并且作为研究产氧光合作用的遗传易处理模型生物。除蓝细菌门外，其他八个细菌门，即变形菌门/假单胞菌门、绿菌门、绿弯菌门、芽孢杆菌门、酸杆菌门、芽单胞菌门、硫化叶菌门和黏球菌门，至少包含一种假定的叶绿素光养物种，它们都进行不产生氧气作为副产物的无氧光合作用变体。这些叶绿素光养生物在它们定殖的栖息地以及它们的生物化学、生理学和新陈代谢方面表现出令人难以置信的多样性，在它们产生的用于利用太阳能的光捕获复合物和色素方面存在差异。虽然有些已经被很好地理解，比如变形菌门的“紫色细菌”，但其他一些直到最近几年才被鉴定出来，因此我们对它们了解相对较少——尤其是那些尚未被分离和培养的。在本章中，我们旨在总结和比较来自发现它们的九个门的叶绿素光养成员的光合生理学和中心代谢过程，给出简短的历史视角并突出我们理解上的差距。
