Biogeochemistry of Earth before exoenzymes
Biogeochemistry of Earth before exoenzymes
复制标题
外酶出现之前地球的生物地球化学
DOI：
10.1038/s41561-023-01266-4
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发表时间：
2023
影响因子：
18.3
通讯作者：
Konhauser, Kurt O.
中科院分区：
文献类型：
--
作者：
Mahmoudi, Nagissa;Steen, Andrew D.;Halverson, Galen P.;Konhauser, Kurt O.
转化和氧化有机物质(即异养生物)的微生物在海洋中关键元素的地球化学循环中发挥着基础性作用。异养微生物通过它们的生长和活动，降解了浮游植物在表层海洋中产生的大部分有机物质，导致营养物质和碳的再生和重新分配回到水体中。然而，大多数有机物在物理上太大，不能被异养微生物直接吸收。因此，许多异养生物会分泌外源酶，将细胞外的大分子分解成更小的底物，然后被细胞直接吸收。微生物用来分泌这些酶的生化系统的复杂性表明，它们不太可能存在于最早的异养生物中。在外源酶之前的海洋中，异养微生物只能接触到一小部分有机物，因此大多数死亡的浮游植物生物量将直接通过水柱并定居在海底。在这里，我们综合现有的地质生物学证据，研究在早期海洋中没有外源酶的情况下有机物的命运。我们认为，在外源酶存在之前的地球上，有机质保存、金属利用率和磷回收的运作方式将与当代地球不同。
Microorganisms that transform and oxidize organic material (that is, heterotrophs) play a fundamental role in the geochemical cycling of key elements in the ocean. Through their growth and activity, heterotrophic microorganisms degrade much of the organic matter produced by phytoplankton in the surface ocean, leading to the regeneration and redistribution of nutrients and carbon back into the water column. However, most organic matter is physically too large to be taken up directly by heterotrophic microorganisms. Consequently, many heterotrophs secrete exoenzymes that break down large molecules outside the cell into smaller substrates that can then be directly taken up by the cell. The complex nature of the biochemical systems that microorganisms use to secrete these enzymes suggests that they were unlikely to have been present in the earliest heterotrophs. In a pre-exoenzyme ocean, heterotrophic microorganisms would only be able to access a small fraction of organic matter such that most dead phytoplankton biomass would have passed directly through the water column and settled onto the seafloor. Here we synthesize existing geobiological evidence to examine the fate of organic matter in the absence of exoenzymes in early oceans. We propose that on an Earth before exoenzymes, organic matter preservation, metal availability and phosphorus recycling would have operated differently than they do on the contemporary Earth.
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影响因子：
3.7
作者：
Green ER;Mecsas J
通讯作者：
Mecsas J
影响因子：
4.9
作者：
A. Noble;D. Ohnemus;N. Hawco;P. Lam;M. Saito
通讯作者：
A. Noble;D. Ohnemus;N. Hawco;P. Lam;M. Saito
DOI：
10.1073/pnas.2103511118
发表时间：
2021-10-05
影响因子：
11.1
作者：
Fakhraee, Mojtaba;Tarhan, Lidya G.;Reinhard, Christopher T.
通讯作者：
Reinhard, Christopher T.
影响因子：
64.8
作者：
Cuskin F;Lowe EC;Temple MJ;Zhu Y;Cameron E;Pudlo NA;Porter NT;Urs K;Thompson AJ;Cartmell A;Rogowski A;Hamilton BS;Chen R;Tolbert TJ;Piens K;Bracke D;Vervecken W;Hakki Z;Speciale G;Munōz-Munōz JL;Day A;Peña MJ;McLean R;Suits MD;Boraston AB;Atherly T;Ziemer CJ;Williams SJ;Davies GJ;Abbott DW;Martens EC;Gilbert HJ
通讯作者：
Gilbert HJ
双刃剑：硫酸盐在地球历史缺氧海洋磷循环中的作用
影响因子：
5.2
作者：
M. Kipp
通讯作者：
M. Kipp