Subglacial erosion has the potential to sustain microbial processes in Subglacial Lake Whillans, Antarctica
Subglacial erosion has the potential to sustain microbial processes in Subglacial Lake Whillans, Antarctica
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DOI：
10.1038/s43247-021-00202-x
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发表时间：
2021-06-29
影响因子：
7.9
通讯作者：
Priscu, John
中科院分区：
文献类型：
--
作者：
Gill-Olivas, Beatriz;Telling, Jon;Priscu, John
冰川下的惠兰斯湖位于南极冰层下约800米的地方，与维持生命的光合作用有机物质的新鲜来源隔绝。因此，湖内和下面沉积物的微生物生态系统的多样性依赖于残余的、覆盖的、海洋来源的有机物和矿物来源的能量的组合。在这里，我们进行了实验来复制冰下侵蚀，包括温和和高能破碎冰下湖惠兰斯沉积物和随后添加缺氧水。我们发现大量的还原物质，包括氢、甲烷、醋酸盐和铵，以及氧化物质，如过氧化氢、硫酸盐和二氧化碳被释放出来。我们提出，氢和过氧化氢的同时存在，以及高浓度的矿物表面自由基，表明水在新磨损的矿物表面上的分裂增加了岩石-水反应的氧化还原对的浓度，并可能提供一种机制来增加微生物生态系统的可用能量。冰川下的侵蚀使岩石破碎和湿润，从而产生可以促进微生物活动的化合物，对从南极洲惠兰斯冰川下湖收集的材料进行的实验证明了这一点
Subglacial Lake Whillans lies below around 800m of Antarctic ice and is isolated from fresh sources of photosynthetic organic matter to sustain life. The diverse microbial ecosystems within the lake and underlying sediments are therefore dependent on a combination of relict, overridden, marine-derived organic matter and mineral-derived energy. Here, we conduct experiments to replicate subglacial erosion involving both gentle and high-energy crushing of Subglacial Lake Whillans sediments and the subsequent addition of anoxic water. We find that substantial quantities of reduced species, including hydrogen, methane, acetate and ammonium and oxidised species such as hydrogen peroxide, sulfate and carbon dioxide are released. We propose that the concomitant presence of both hydrogen and hydrogen peroxide, alongside high concentrations of mineral surface radicals, suggests that the splitting of water on freshly abraded mineral surfaces increases the concentrations of redox pairs from rock-water reactions and could provide a mechanism to augment the energy available to microbial ecosystems. The crushing and wetting of rocks by erosion under glaciers produces chemical compounds that could fuel microbial activity, as demonstrated by experiments on material collected from Subglacial Lake Whillans in Antarctica