Palaeoecology of a billion-year-old non-marine cyanobacterium from the Torridon Group and Nonesuch Formation.
Palaeoecology of a billion-year-old non-marine cyanobacterium from the Torridon Group and Nonesuch Formation.
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DOI：
10.1111/pala.12212
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发表时间：
2016-01
期刊：
影响因子：
2.6
通讯作者：
Wellman CH
中科院分区：
文献类型：
--
作者：
Strother PK;Wellman CH
一种新的chroococcalean蓝细菌被描述为来自苏格兰Torridonian群和美国密歇根州Nonesuch组的大约10亿年的非海洋沉积物。新微体化石湖泊始盐藻Eohalothece lacustrina gen. et sp. nov.的单个细胞，与底栖微生物生物膜有关，但大多数样品是在孢粉学制备物中回收的，其形式是大型的、明显的浮游菌落，类似于现存的微囊藻属物种。在Torridonian，Eohalothece与磷酸盐结核，我们已经开发了一种新的假说连接Eohalothece磷酸盐沉积在古代淡水环境。现存的蓝细菌可以是胞外微囊藻毒素的多产者，所述胞外微囊藻毒素是非核糖体多肽磷酸酶抑制剂。微囊藻毒素可能促进了沉积有机磷酸盐的保留和浓度之前，矿化的水藻和结核的形成。这进一步表明，托里多尼亚湖泊是氮限制的微囊藻毒素的释放是在这样的条件下，今天的增强。Eohalothece lacustrina的丰度和广泛的分布证明了蓝藻作为产氧光合自养生物在湖泊生态系统中的重要性，在中元古代-新元古代的过渡。
A new chroococcalean cyanobacterium is described from approximately 1‐billion‐year‐old non‐marine deposits of the Torridonian Group of Scotland and the Nonesuch Formation of Michigan, USA. Individual cells of the new microfossil, Eohalothece lacustrina gen. et sp. nov., are associated with benthic microbial biofilms, but the majority of samples are recovered in palynological preparations in the form of large, apparently planktonic colonies, similar to extant species of Microcystis. In the Torridonian, Eohalothece is associated with phosphatic nodules, and we have developed a novel hypothesis linking Eohalothece to phosphate deposition in ancient freshwater settings. Extant cyanobacteria can be prolific producers of extracellular microcystins, which are non‐ribosomal polypeptide phosphatase inhibitors. Microcystins may have promoted the retention and concentration of sedimentary organic phosphate prior to mineralization of francolite and nodule formation. This has a further implication that the Torridonian lakes were nitrogen limited as the release of microcystins is enhanced under such conditions today. The abundance and wide distribution of Eohalothece lacustrina attests to the importance of cyanobacteria as oxygen‐producing photoautotrophs in lacustrine ecosystems at the time of the Mesoproterozoic–Neoproterozoic transition.