Heijs S K, Aloisi G, Bouloubassi I, Pancost R D, Pierre C, Sinninghe Damsté J S, Gottschal J C, van Elsas J D, Forney L J
Department of Microbiology, Center of Ecological and Evolutionary Studies, University of Groningen, P.O. Box 14, 9750 AA, Haren, The Netherlands.
Microb Ecol. 2006 Oct;52(3):451-62. doi: 10.1007/s00248-006-9099-8. Epub 2006 Aug 15.
Carbonate crusts in marine environments can act as sinks for carbon dioxide. Therefore, understanding carbonate crust formation could be important for understanding global warming. In the present study, the microbial communities of three carbonate crust samples from deep-sea mud volcanoes in the eastern Mediterranean were characterized by sequencing 16S ribosomal RNA (rRNA) genes amplified from DNA directly retrieved from the samples. In combination with the mineralogical composition of the crusts and lipid analyses, sequence data were used to assess the possible role of prokaryotes in crust formation. Collectively, the obtained data showed the presence of highly diverse communities, which were distinct in each of the carbonate crusts studied. Bacterial 16S rRNA gene sequences were found in all crusts and the majority was classified as alpha-, gamma-, and delta- Proteobacteria. Interestingly, sequences of Proteobacteria related to Halomonas and Halovibrio sp., which can play an active role in carbonate mineral formation, were present in all crusts. Archaeal 16S rRNA gene sequences were retrieved from two of the crusts studied. Several of those were closely related to archaeal sequences of organisms that have previously been linked to the anaerobic oxidation of methane (AOM). However, the majority of archaeal sequences were not related to sequences of organisms known to be involved in AOM. In combination with the strongly negative delta 13C values of archaeal lipids, these results open the possibility that organisms with a role in AOM may be more diverse within the Archaea than previously suggested. Different communities found in the crusts could carry out similar processes that might play a role in carbonate crust formation.
海洋环境中的碳酸盐结壳可以充当二氧化碳的汇。因此，了解碳酸盐结壳的形成对于理解全球变暖可能很重要。在本研究中，通过对从东地中海深海泥火山的三个碳酸盐结壳样品中直接提取的DNA扩增的16S核糖体RNA（rRNA）基因进行测序，对其微生物群落进行了表征。结合结壳的矿物组成和脂质分析，序列数据被用于评估原核生物在结壳形成中的可能作用。总体而言，所获得的数据表明存在高度多样化的群落，在所研究的每个碳酸盐结壳中都各不相同。在所有结壳中都发现了细菌16S rRNA基因序列，其中大多数被归类为α-、γ-和δ-变形菌门。有趣的是，与盐单胞菌属和盐弧菌属相关的变形菌门序列在所有结壳中都存在，它们在碳酸盐矿物形成中可以发挥积极作用。从所研究的两个结壳中检索到了古菌16S rRNA基因序列。其中一些与先前与甲烷厌氧氧化（AOM）相关的生物的古菌序列密切相关。然而，大多数古菌序列与已知参与AOM的生物序列无关。结合古菌脂质强烈的负δ13C值，这些结果表明在古菌中，参与AOM的生物可能比以前认为的更加多样化。在结壳中发现的不同群落可能执行类似的过程，这些过程可能在碳酸盐结壳的形成中发挥作用。
