The role of oxygen conditions in the microbial dissolution of biogenic silica under brackish conditions
The role of oxygen conditions in the microbial dissolution of biogenic silica under brackish conditions
复制标题
微咸条件下氧气条件在生物二氧化硅微生物溶解中的作用
作者：
Mari Lehtimäki;H. Sinkko;P. Tallberg
生物硅（BSi）的再生对于水生生态系统中硅藻的持续溶解硅（DSi）供应至关重要，这些初级生产者在碳（C）下降中发挥重要作用。已经在例如波罗的海的贫氧（O2）底层沃茨中检测到增加的DSi浓度，波罗的海是世界上最大的缺氧或低氧海洋区域之一。由于低氧可能在沿海地区也变得更加频繁，因此应探讨亚氧条件对硅（Si）循环的影响。为研究低氧对微生物介导的硅藻碎屑和沉积物向微咸水中释放DSi的影响，进行了间歇实验室试验。缺氧条件有利于更完全的溶解硅藻比好氧条件。然而，年龄，来源和生理条件的BSi显着影响溶解速率，和沉积物的存在下，BSi溶解。抑制细菌活性减少溶解硅藻在有氧和缺氧条件下，和16 S rRNA基因的T-RFLP证实，O2条件影响的细菌群落的组成。综上所述，这些结果表明，氧气条件和微生物在硅藻BSi的再生中起着重要作用。此外，结果可以解释与O2耗尽在波罗的海的底部沃茨的DSi浓度升高。
Regeneration of biogenic silica (BSi) is essential for the constant supply of dissolved silica (DSi) to diatoms in aquatic ecosystems, where these primary producers play an important role in carbon (C) drawdown. Increased DSi concentrations have been detected in the oxygen (O2) depleted bottom waters of e.g. the brackish Baltic Sea, which is suffering from one of the largest anoxic or hypoxic marine areas in the world. As hypoxia is likely to become more frequent also in coastal areas, the effects of suboxic conditions on the silicon (Si) cycle should be explored. To examine the effects of hypoxia on microbially mediated DSi release from diatom detritus and sediment to brackish seawater, a batch laboratory experiment was conducted. Hypoxic conditions facilitated more complete dissolution of diatoms than oxic conditions. However, the age, origin and physiological condition of the BSi significantly affected the dissolution rate, and the presence of sedimentary material decreased BSi dissolution. Inhibition of bacterial activity reduced the dissolution of diatoms under both oxic and hypoxic conditions, and T-RFLP of 16S rRNA genes confirmed that O2 conditions affected the composition of the bacterial community. Taken together, these results demonstrate that oxygen conditions and microbes play a fundamental role in regeneration of diatom BSi. Moreover, the results may explain the elevated DSi concentrations associated with O2 depletion in the bottom waters of the Baltic Sea.
DOI：
10.1073/pnas.82.20.6955
发表时间：
1985-01-01
影响因子：
11.1
作者：
LANE, DJ;PACE, B;PACE, NR
通讯作者：
PACE, NR