Quantifying the contribution of the deep biosphere in the marine sediment carbon cycle using deep-sea sediment cores from the Baltic Sea

使用波罗的海深海沉积物岩心量化深层生物圈在海洋沉积物碳循环中的贡献

• 批准号: 1431598
• 负责人: Karen Lloyd
• 金额: $ 36.21万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1431598&HistoricalAwards=false
• 关键词: Quantifying; contribution; deep; biosphere; marine

Marine sediments contain a microbial population large enough to rival that of Earth's oceans, but much about this vast community is unknown. Innovations in total cell counting methods have refined estimates of cell concentrations, but tell us nothing about specific taxa. Isotopic data provides evidence that a majority of subsurface microorganisms survive by breaking down organic matter, yet measurable links between specific microbial taxa and their organic matter substrates are untested. The proposed work overcomes these limitations, with a particular focus on the degradation of proteins and carbohydrates, which comprise the bulk of classifiable sedimentary organic matter. The project will link specific taxa to potential extracellular enzyme activity in the genomes of single microbial cells, apply newly-identified, optimal methods for counting viable cells belonging to specific taxa using catalyzed reporter deposition fluorescent in situ hybridization (CARD-FISH), and measure the potential activity of their enzymes in situ. The resulting data will provide key evidence about the strategies subsurface life uses to overcome extreme energy limitation and contribute to the long-term carbon cycle. The Principal Investigators are employing novel,improved methods to quantify cells of specific taxa in the marine subsurface and to determine the biogeochemical functions of those uncultured taxa, including: 1)Determine the pathway of organic carbon degradation in single cell genomes of uncultured, numerically dominant subsurface microorganisms. 2)Quantify viable bacteria and archaea in the deep subsurface using an improvement on the existing technology of CARD-FISH. 3)Measure the potential activities (Vmax values) of enzymes in deep Baltic Sea sediments, and use the abundances of enzyme-producing microorganisms to calculate depth profiles of cell-specific Vmax values. The project combines these methods in order to identify and quantify the cells capable of degrading organic matter in deep sediments of the Baltic Sea, obtained from Integrated Ocean Drilling Program (IODP) expedition 347. These results will greatly expand our knowledge of the function and activity of uncultured microorganisms in the deep subsurface.

海洋沉积物包含足够大的微生物种群，足以与地球的海洋相抗衡，但是关于这个庞大的社区的许多人尚不清楚。总细胞计数方法的创新已经完善了细胞浓度的估计值，但对特定分类单元的了解一无所知。同位素数据提供了证据表明，大多数地下微生物通过分解有机物而生存，但是未经测试的特定微生物分类群及其有机物基板之间的可测量联系。拟议的工作克服了这些局限性，特别着眼于蛋白质和碳水化合物的降解，其中包括大部分可分类的沉积有机物。该项目将将特定的分类单元与单个微生物细胞基因组中的潜在细胞外酶活性联系起来，采用新识别的，最佳的方法，用于计算使用催化的报道荧光原位杂交（card-fish）（card-fish）属于特定分类单元的可行细胞，并测量其enzymes inspote的潜在活性。最终的数据将提供有关策略地下生命用途来克服极端能量限制并有助于长期碳循环的关键证据。首席研究人员正在采用新颖的改进方法来量化海洋地下特定分类单元的细胞，并确定那些未培养的类群的生物地球化学功能，包括：1）确定有机碳降解在未培养的单个细胞基因组中未培养的，数值显着的地下微生物的途径。 2）使用现有的鱼类技术技术来量化深度地下的可行细菌和古细菌。 3）测量深波罗的海沉积物中酶的潜在活性（VMAX值），并利用大量产生酶的微生物来计算细胞特异性VMAX值的深度谱。该项目结合了这些方法，以识别和量化能够从综合海洋钻井程序（IODP）Expedition 347中获得的能够降解有机物的细胞。这些结果将大大扩展我们对深地下表面中未养殖微生物的功能和活性的了解。