Photoferrotrophs thrive in an Archean Ocean analogue

摘要: Abstract Considerable discussion surrounds the potential role of anoxygenic phototrophic Fe(II)-oxidizing bacteria in both genesis Banded Iron Formations (BIFs) and early marine productivity. However, phototrophs have yet to be identified modern environments with comparable chemistry physical structure ancient Fe(II)-rich (ferruginous) oceans from which BIFs deposited. Lake Matano, Indonesia, eighth deepest lake world, is such an environment. Here, sulfate scarce ( 100-m-deep chemocline. Within this sulfide-poor, Fe(II)-rich, illuminated chemocline, we find a populous assemblage green sulfur (GSB). These GSB represent large component Matano community, bacteriochlorophyll e, pigment produced by low-light-adapted GSB, nearly as abundant chlorophyll lake's euphotic surface waters. The dearth sulfide chemocline requires that are sustained oxidation Fe(II), supply. By analogy, propose similar microbial communities, including populations reducers photoferrotrophic likely populated chemoclines ferruginous oceans, driving fueling anoxygenic photosynthesis banded iron formation green bacteria iron oxidation Lake