Nucleic acid concentrations (DNA, RNA) in the continental and deep-sea sediments of the eastern Mediterranean: relationships with seasonally varying organic inputs and bacterial dynamics
Nucleic acid concentrations (DNA, RNA) in the continental and deep-sea sediments of the eastern Mediterranean: relationships with seasonally varying organic inputs and bacterial dynamics
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DOI：
10.1016/s0967-0637(98)00101-0
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发表时间：
1999-06-01
影响因子：
2.4
通讯作者：
Fabiano, M
中科院分区：
文献类型：
--
作者：
Danovaro, R;Dell'anno, A;Fabiano, M
为了研究极端贫营养的安达卢西亚海大陆架和深海沉积物中遗传物质的时间变化，1994年8月至1995年9月，在7个站位（40至1540 m深度）用多芯取样器按季节采集样品。对表层沉积物（0-1 cm）进行二次取样，分析核酸含量（DNA、RNA）和细菌密度。沉积物中的DNA浓度很高（年平均值为25.0 μ g/g），并随着水深的增加而下降，范围为3.5至55.2 μ g/g。DNA浓度在半深海深度也显示出广泛的时间变化，证实了最近关于深海环境变化很大的观点。RNA浓度也随着水深的增加而降低（范围为0.4-29.9 μ g/g）。RNA与DNA的比例没有显示出明确的空间格局，但其特点是采样期间之间的显着变化。DNA浓度显着相关的沉积物中的蛋白质和植物色素的浓度，表明可能的关系与输入的初级有机质从透光层。与其他深海环境相比，细菌密度一般较高（范围：0.9-4.6 x 10（8）个细胞g（-1）），并随着水深的增加而降低。细菌对沉积物遗传物质的贡献估计表明，细菌DNA占年平均总DNA池的一小部分（4.3%），但细菌RNA占总沉积物RNA的一个重要部分（26%）。细菌对核酸的贡献随着深度的增加而增加，尽管是不规则的。在深海沉积物中，RNA浓度的变化似乎在很大程度上取决于细菌动力学。对DNA库的总体生物贡献（即微生物加小型底栖动物DNA）的估计表明，地中海东部大陆和深海沉积物中的绝大多数（约90%）DNA是碎屑。非活体DNA池达到极高的浓度，高达0.41 g DNA m（-2）cm（-1）。因此，特别是在深海底栖生境，其特点是低投入的不稳定的有机化合物，碎屑DNA可以代表一个合适的和高质量的食物来源或一个重要的水库的核酸前体的底栖代谢。(C)1999 Elsevier Science Ltd.版权所有。
In order to study temporal variations of the genetic material in the continental shelf and deep-sea sediments of the extremely oligotrophic Cretan Sea, samples were collected on seasonal basis from August 1994 to September 1995, with a multiple corer, at seven stations (from 40 to 1540 m depth). Surface sediments (0-1 cm) were sub-sampled and analyzed for nucleic acid content (DNA, RNA) and bacterial density. DNA concentrations in the sediments were high (on annual average, 25.0 mu g g(-1)) and declined with increasing water depth, ranging from 3.5 to 55.2 mu g g(-1). DNA concentrations displayed wide temporal changes also at bathyal depths confirming the recent view of the large variability of the deep-sea environments. Also RNA concentrations decreased with increasing water depth (range, 0.4-29.9 mu g g(-1)). The ratio of RNA to DNA did not show a clear spatial pattern but was characterized by significant changes between sampling periods. DNA concentrations were significantly correlated with protein and phytopigment concentrations in the sediment, indicating a possible relationship with the inputs of primary organic matter from the photic layer. Bacterial densities were generally high (range: 0.9-4.6 x 10(8) cells g(-1)) compared to other deep-sea environments and decreased with increasing water depth. Estimates of the bacterial contribution to the sedimentary genetic material indicated that bacterial-DNA accounted, on annual average, for a small fraction of the total DNA pool (4.3%) but that bacterial-RNA represented a significant fraction of the total sedimentary RNA (26%). Bacterial contribution to nucleic acids increased, even though irregularly, with increasing depth. In deep-sea sediments, changes in RNA concentrations appear to be largely dependent upon bacterial dynamics. Estimates of the overall living contribution to the DNA pools (i.e. microbial plus meiofaunal DNA) indicated that the large majority (about 90%) of the DNA in continental and deep-sea sediments of the eastern Mediterranean was detrital. The non-living DNA pools reach extremely high concentrations up to 0.41 g DNA m(-2) cm(-1). Thus, especially in deep benthic habitats, characterized by low inputs of labile organic compounds, detrital DNA could represent a suitable and high quality food source or a significant reservoir of nucleic acid precursors for benthic metabolism. (C) 1999 Elsevier Science Ltd. All rights received.