Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC, USA; Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA.
Environ Microbiol Rep. 2014 Apr;6(2):159-66. doi: 10.1111/1758-2229.12137. Epub 2014 Jan 16.
Subaerial explosive volcanism contributes substantial amounts of material to the oceans, but little is known about the impact of volcanic ash on sedimentary microbial activity. We have studied anammox communities in deep sea sediments near the volcanically active island of Montserrat, Lesser Antilles. The rates of anammox and denitrification in the sediments were measured using (15)N isotope pairing incubation experiments, while 16S rRNA genes were used to examine anammox community structures. The higher anammox rates were measured in sediment containing the lower accumulation of volcanic ash in the surface sediments, while the lowest activities were found in sediments with the highest ash deposit. 16S rRNA gene analysis revealed the presence of 'Candidatus Scalindua spp.' in the sediments. The lowest diversity of anammox bacteria was observed in the sediments with the highest ash deposit. Overall, this study demonstrates that the deposition of volcanic material in deep sea sediments has negative impacts on activity and diversity of the anammox community. Since anammox may account for up to 79% of N2 production in marine ecosystems, periods of extensive explosive volcanism in Earth history may have had a hitherto unrecognized negative impact on the sedimentary nitrogen removal processes.
陆上喷发的火山活动向海洋输送了大量物质，但火山灰对沉积微生物活性的影响却知之甚少。我们研究了小安的列斯群岛中活跃的蒙特塞拉特火山附近深海沉积物中的厌氧氨氧化群落。通过（15）N 同位素配对培养实验测量了沉积物中的厌氧氨氧化和反硝化速率，同时使用 16S rRNA 基因来检测厌氧氨氧化群落结构。在含有较低表面沉积物中火山灰积累的沉积物中测量到较高的厌氧氨氧化速率，而在具有最高灰烬沉积物的沉积物中发现了最低的活性。16S rRNA 基因分析表明沉积物中存在“Candidatus Scalindua spp.”。在具有最高灰分沉积物的沉积物中观察到厌氧氨氧化细菌的多样性最低。总体而言，这项研究表明，深海沉积物中火山物质的沉积对厌氧氨氧化群落的活性和多样性具有负面影响。由于厌氧氨氧化可能占海洋生态系统中 N2 生成量的高达 79%，因此地球历史上广泛的爆发性火山活动可能对沉积氮去除过程产生了迄今为止尚未被认识到的负面影响。
