美国麻省理工学院Tanja Bosak、Mirna Daye等研究人员合作发现，光驱动厌氧微生物氧化锰。2019年12月4日，《自然》在线发表了这一成果。
研究人员发现在没有分子氧和高电位光合反应中心的情况下，产氧光合微生物群落可生物矿化锰氧化物。在古细菌时代，严格厌氧条件下Mn（II）的微生物氧化产生的地球化学信号与在大氧化事件之前确定氧光合作用演变的信号相同。这种光依赖过程还可能在现代缺氧水体和沉积物的光化带中产生锰氧化物。
据了解，氧合光合作用为现代生物圈提供了有机碳，但尚不清楚这种代谢何时产生。以前曾有人提出基于推断出古生界沉积岩中锰氧化物的存在，能够分解水的光合作用反应中心出现在大约30亿年前。但是，这假定只有在分子氧、活性氧或高电位光合反应中心的存在下才能生产锰氧化物。
附：英文原文
Title: Light-driven anaerobic microbial oxidation of manganese
Author: Mirna Daye, Vanja Klepac-Ceraj, Mihkel Pajusalu, Sophie Rowland, Anna Farrell-Sherman, Nicolas Beukes, Nobumichi Tamura, Gregory Fournier, Tanja Bosak
Issue&Volume: 2019-12-04
Abstract: Oxygenic photosynthesis supplies organic carbon to the modern biosphere, but it is uncertain when this metabolism originated. It has previously been proposed1,2 that photosynthetic reaction centres capable of splitting water arose by about 3 billion years ago on the basis of the inferred presence of manganese oxides in Archaean sedimentary rocks. However, this assumes that manganese oxides can be produced only in the presence of molecular oxygen3, reactive oxygen species4,5 or by high-potential photosynthetic reaction centres6,7. Here we show that communities of anoxygenic photosynthetic microorganisms biomineralize manganese oxides in the absence of molecular oxygen and high-potential photosynthetic reaction centres. Microbial oxidation of Mn(ii) under strictly anaerobic conditions during the Archaean eon would have produced geochemical signals identical to those used to date the evolution of oxygenic photosynthesis before the Great Oxidation Event1,2. This light-dependent process may also produce manganese oxides in the photic zones of modern anoxic water bodies and sediments. Anoxygenic photosynthetic microorganisms can biomineralize manganese oxides without molecular oxygen being present and without high-potential photosynthetic reaction centres, which sheds doubt on proposed dates for the origins of oxygenic photosynthetic metabolism.
DOI: 10.1038/s41586-019-1804-0
Source:https://www.nature.com/articles/s41586-019-1804-0
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
