Microbial win in the amount and speed of carbon sink this time.
Based on daily rates of carbon uptake, the team estimates that these microbialites can absorb the equivalent of nine to 16 kilograms of carbon dioxide every year per square meter. That’s like a tennis court-sized area absorbing as much CO2 every year as three acres of forest, making these systems one of the most efficient biological mechanisms for long-term carbon storage observed in nature.
2. Nature Communication (08 December 2025) (https://www.nature.com/articles/s41467-025-66552-8) (https://doi.org/10.1038/s41467-025-66552-8)
Integration of multiple metabolic pathways supports high rates of carbon precipitation in living microbialites
Authors: Rachel E. Sipler, Eric W. Isemonger, Samantha C. Waterworth, Steffen H. Büttner, Thomas G. Bornman, Ross-Lynne A. Gibb, Xavier Siwe Noundou, Siddarthan Venkatachalam & Rosemary A. Dorrington
Abstract: Microbialites are lithifying microbial mats that form multi-layered structures via biological carbon (C) uptake and carbonate precipitation. Here we relate C uptake and precipitation rates to taxonomic diversity and functional capacity of bacterial communities in supratidal freshwater microbialites. Diel assays and analysis of functional gene capacity reveal that photosynthesis is bolstered by light-independent, biological C uptake mechanisms, including biomineralization and chemoautotrophy. Through integration of these mechanisms, microbialites can capture inorganic C over a 24-hour cycle at a rate of 7-12 g C m-2 24 h-1. Notably, up to 87 % of the C taken up is precipitated as inorganic carbon, capturing 2.4 − 4.3 kg C m-2 year-1. Based on observed porosity and laboratory-based accretion rates, this equates to 13-23 mm of vertical calcium carbonate accumulation per year. Hence, contemporary microbialites provide a highly effective biological mechanism to precipitate dissolved CO2 as geologically stable carbonate mineral deposits.
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1. 根據每日碳吸收率，研究團隊估計，這些微生物岩每年每平方公尺(m2)可吸收相當於 9~16 kg的CO2。這相當於一個網球場大小的區域每年吸收的CO2量相當於三英畝(acre)森林，這使得這些系統成為自然界中觀察到的最有效的長期碳儲存生物機制之一。
2. 微生物岩是由微生物墊層形成的岩化體，透過生物碳（C）吸收和碳酸鹽沉澱形成多層結構。本文研究了潮上帶淡水微生物岩中細菌群落的分類多樣性和功能能力與碳吸收和沈澱速率之間的關係。晝夜節律測定和功能基因能力分析表明，光合作用受到光合作用非光依賴性生物碳吸收機制的促進，這些機制包括生物礦化和化能自養。透過整合這些機制，微生物岩可以在24小時週期內以7-12 g C m-2 24 h-1的速率捕獲無機碳。值得注意的是，高達87%的吸收碳以無機碳的形式沉澱，每年捕獲2.4-4.3 kg C m-2。根據觀測到的孔隙率和實驗室測定的沉積速率，這相當於每年垂直方向累積13-23毫米的碳酸鈣。因此，現代微生物岩提供了一種高效的生物機制，可以將溶解的二氧化碳沉澱為地質穩定的碳酸鹽礦物沉積物。
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