Organic Stabilization of Extracellular Elemental Sulfur in a Sulfurovum-Rich Biofilm: A New Role for Extracellular Polymeric Substances?
Organic Stabilization of Extracellular Elemental Sulfur in a Sulfurovum-Rich Biofilm: A New Role for Extracellular Polymeric Substances?
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DOI：
10.3389/fmicb.2021.720101
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发表时间：
2021
影响因子：
5.2
通讯作者：
Cosmidis J
中科院分区：
文献类型：
--
作者：
Cron B;Macalady JL;Cosmidis J
这项工作揭示了胞外聚合物(EPS)在硫氧化细菌产生的元素硫生物矿物质的形成和保存中所起的作用。我们对意大利Frasassi洞穴系统富含硫磺的生物膜中产生的元素硫颗粒进行了表征。颗粒呈球形和双锥状，既有稳定的(α-S8)晶体结构，也有亚稳态的(β-S8)晶体结构。元素硫嵌入EPS的致密基质中，颗粒被富含酰胺和羧基的有机包膜包围。有机包裹和亚稳态晶体结构的存在与元素硫的有机矿化一致，即在有机物存在的情况下元素硫的形成和稳定，这是以前在实验室研究中观察到的机制。本研究为微生物EPS在环境矿物形成中的重要作用提供了新的证据。我们推测，胞外有机物被硫氧化细菌用来稳定细胞壁外的元素硫矿物，作为化学能量的储存。生物膜中能量源(以固体电子受体的形式)的稳定是微生物EPS潜在的新作用，需要进一步研究。
This work shines light on the role of extracellular polymeric substance (EPS) in the formation and preservation of elemental sulfur biominerals produced by sulfur-oxidizing bacteria. We characterized elemental sulfur particles produced within a Sulfurovum-rich biofilm in the Frasassi Cave System (Italy). The particles adopt spherical and bipyramidal morphologies, and display both stable (α-S8) and metastable (β-S8) crystal structures. Elemental sulfur is embedded within a dense matrix of EPS, and the particles are surrounded by organic envelopes rich in amide and carboxylic groups. Organic encapsulation and the presence of metastable crystal structures are consistent with elemental sulfur organomineralization, i.e., the formation and stabilization of elemental sulfur in the presence of organics, a mechanism that has previously been observed in laboratory studies. This research provides new evidence for the important role of microbial EPS in mineral formation in the environment. We hypothesize that the extracellular organics are used by sulfur-oxidizing bacteria for the stabilization of elemental sulfur minerals outside of the cell wall as a store of chemical energy. The stabilization of energy sources (in the form of a solid electron acceptor) in biofilms is a potential new role for microbial EPS that requires further investigation.
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影响因子：
3
作者：
Brandes, JA;Lee, C;Cody, G
通讯作者：
Cody, G
影响因子：
5
作者：
Findlay, Alyssa J.;Gartman, Amy;Luther, George W., III
通讯作者：
Luther, George W., III
影响因子：
9.7
作者：
Artz, Rebekka R. E.;Chapman, Stephen J.;Francez, Andre-Jean
通讯作者：
Francez, Andre-Jean
影响因子：
5
作者：
Chan, Clara S.;Fakra, Sirine C.;Banfield, Jillian F.
通讯作者：
Banfield, Jillian F.
影响因子：
16.6
作者：
Cosmidis, Julie;Templeton, Alexis S.
通讯作者：
Templeton, Alexis S.