Low temperature S0 biomineralization at a supraglacial spring system in the Canadian High Arctic
Low temperature S0 biomineralization at a supraglacial spring system in the Canadian High Arctic
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DOI：
10.1111/j.1472-4669.2011.00283.x
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发表时间：
2011-07-01
期刊：
影响因子：
3.7
通讯作者：
Templeton, A. S.
中科院分区：
文献类型：
--
作者：
Gleeson, D. F.;Williamson, C.;Templeton, A. S.
元素硫（S-0）沉积到表面冰在Borup峡湾通过埃尔斯米尔岛，加拿大，每年夏天，当高浓度的水溶液H2S从冰上泉系统排放。由硫沉积物产生的16 S rRNA基因克隆文库由β-变形菌门，特别是罗尔斯通氏菌属（Ralstonia sp.）和ε-变形菌，如硫弯菌属（Sulfuricurvales）和硫腐菌属（Sulfurovumales spp.）也很丰富。同时培养实验分离出嗜冷的硫化物氧化聚生体，其在相反的Na 2S和氧气梯度中产生S-0。16 S rRNA基因分析的硫沉淀在梯度管显示稳定的硫生物矿化财团占主导地位的海蛞蝓属与希瓦氏菌，Loktanella，Rubrobacter，黄杆菌属，鞘氨醇单胞菌属。与栽培品种密切相关的生物出现在环境16 S rRNA克隆库中;目前已知没有氧化硫化物。聚生菌曾经被简化为Marinobacteria和Flavobacteria spp。通过稀释至消失和琼脂去除，硫生物矿化继续进行。希瓦氏菌属（Shewanella）、洛克坦氏菌属（Loktanella）、鞘氨醇单胞菌属（Sphingomonas）和Devosia spp.也分离异养培养基，但没有产生S-0单独时，重新引入Na 2S梯度管。接种海蛙和希瓦氏菌属的试管共培养确实显示了硫的生物矿化作用，这表明Marinidae可能是实验室实验中关键的硫化物氧化剂。光，荧光和扫描电子显微镜下的矿物聚集体在Marinidae实验中发现丰富的细胞，与纤维和鞘矿化与细胞外亚微米硫颗粒;类似的生物矿化没有观察到在非生物控制。与低温微生物硫循环相关的矿物产品的详细表征可能为未来的木卫二和火星探索提供生物特征。
Elemental sulfur (S-0) is deposited each summer onto surface ice at Borup Fiord pass on Ellesmere Island, Canada, when high concentrations of aqueous H2S are discharged from a supraglacial spring system. 16S rRNA gene clone libraries generated from sulfur deposits were dominated by beta-Proteobacteria, particularly Ralstonia sp. Sulfur-cycling micro-organisms such as Thiomicrospira sp., and epsilon-Proteobacteria such as Sulfuricurvales and Sulfurovumales spp. were also abundant. Concurrent cultivation experiments isolated psychrophilic, sulfide-oxidizing consortia, which produce S-0 in opposing gradients of Na2S and oxygen. 16S rRNA gene analyses of sulfur precipitated in gradient tubes show stable sulfur-biomineralizing consortia dominated by Marinobacter sp. in association with Shewanella, Loktanella, Rubrobacter, Flavobacterium, and Sphingomonas spp. Organisms closely related to cultivars appear in environmental 16S rRNA clone libraries; none currently known to oxidize sulfide. Once consortia were simplified to Marinobacter and Flavobacteria spp. through dilution-to-extinction and agar removal, sulfur biomineralization continued. Shewanella, Loktanella, Sphingomonas, and Devosia spp. were also isolated on heterotrophic media, but none produced S-0 alone when reintroduced to Na2S gradient tubes. Tubes inoculated with a Marinobacter and Shewanella spp. co-culture did show sulfur biomineralization, suggesting that Marinobacter may be the key sulfide oxidizer in laboratory experiments. Light, florescence and scanning electron microscopy of mineral aggregates produced in Marinobacter experiments revealed abundant cells, with filaments and sheaths variably mineralized with extracellular submicron sulfur grains; similar biomineralization was not observed in abiotic controls. Detailed characterization of mineral products associated with low temperature microbial sulfur-cycling may provide biosignatures relevant to future exploration of Europa and Mars.