EA 4592, Géoressources & Environnement, Ensegid, Bordeaux INP, Pessac, France.
Université Bordeaux Montaigne, Pessac, France.
Geobiology. 2018 Jul;16(4):378-398. doi: 10.1111/gbi.12281. Epub 2018 Mar 23.
In modern stromatolites, mineralization results from a complex interplay between microbial metabolisms, the organic matrix, and environmental parameters. Here, we combined biogeochemical, mineralogical, and microscopic analyses with measurements of metabolic activity to characterize the mineralization processes and products in an emergent (<18 months) hypersaline microbial mat. While the nucleation of Mg silicates is ubiquitous in the mat, the initial formation of a Ca-Mg carbonate lamina depends on (i) the creation of a high-pH interface combined with a major change in properties of the exopolymeric substances at the interface of the oxygenic and anoxygenic photoautotrophic layers and (ii) the synergy between two major players of sulfur cycle, purple sulfur bacteria, and sulfate-reducing bacteria. The repetition of this process over time combined with upward growth of the mat is a possible pathway leading to the formation of a stromatolite.
在现代叠层石中，矿化作用是微生物代谢、有机基质和环境参数之间复杂相互作用的结果。在这里，我们结合生物地球化学、矿物学和微观分析以及代谢活性测量来描述一个新兴（<18 个月）高盐微生物席的矿化过程和产物。虽然镁硅酸盐的成核在席子中普遍存在，但钙镁碳酸盐层的初始形成取决于 (i) 高 pH 界面的形成，以及好氧和缺氧光合作用层界面上的胞外聚合物物质性质的重大变化，以及 (ii) 硫循环中的两个主要参与者——紫色硫细菌和硫酸盐还原菌之间的协同作用。随着时间的推移，这种过程的重复以及席子的向上生长是形成叠层石的一种可能途径。
