Seasonal Changes in Organic Matter Mineralization in a Sublittoral Sediment and Temperature-Driven Decoupling of Key Processes
Seasonal Changes in Organic Matter Mineralization in a Sublittoral Sediment and Temperature-Driven Decoupling of Key Processes
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DOI：
10.1007/s00248-010-9659-9
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发表时间：
2010-04
影响因子：
3.6
通讯作者：
K. Tabuchi;Hisaya Kojima;M. Fukui
中科院分区：
文献类型：
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作者：
K. Tabuchi;Hisaya Kojima;M. Fukui
研究了日本东京湾温带亚滨海沉积物中有机化合物矿化的季节变化。总矿化率和硫酸盐还原率在全年中表现出较大的季节变化，虽然两者的波动都与温度有关，但后者在5月份不规则地高。间隙水中溶解有机碳浓度在4月份特别高。在与季节变化相适应的温度下进行了基于培养的实验。在4月对应温度（13℃）培养的培养基中，水解和发酵进行，但终端氧化受阻，导致乙酸积累。在与5月（22°C）对应的温度下，观察到乙酸氧化与硫酸盐还原耦合。温度相关的差异也反映在DGGE分析的培养物中的细菌群落结构上。在低温培养中检测到不完全氧化剂的硫酸盐还原菌，而在高温培养中发现的序列与完全氧化剂有关。这些结果表明，完全氧化和不完全氧化硫酸盐还原细菌作为不同的功能群，以不同的方式响应温度，特别是在温度波动较大的环境中。
Seasonal changes in the mineralization of organic compounds in sediments were investigated in temperate, sublittoral zone sediments (Tokyo Bay, Japan). The total mineralization rate and sulfate reduction rate showed large seasonal variations over the year, and although the fluctuations in both rates correlated with temperature, the latter was irregularly high in May. The concentration of organic carbon dissolved in interstitial water was specifically high in April. A culture-based experiment was also conducted under temperatures corresponding to the seasonal changes. In the culture incubated at a temperature corresponding to April (13 °C), hydrolysis and fermentation proceeded, but terminal oxidation was hindered, thereby resulting in acetate accumulation. At a temperature corresponding to May (22 °C), acetate oxidation coupled with sulfate reduction was observed. The temperature-related differences were also reflected in the bacterial community structure in the cultures analyzed by DGGE. In the culture incubated at the lower temperature, sulfate-reducing bacterium of incomplete oxidizer was detected, while sequence found in the culture incubated at the higher temperature was related to complete oxidizers. These results suggest that complete and incomplete-oxidizing sulfate-reducing bacteria act as distinct functional groups, responding to temperature in different ways, particularly in environments characterized by large temperature fluctuations.