Microsensor Measurements of Sulfate Reduction and Sulfide Oxidation in Compact Microbial Communities of Aerobic Biofilms
Microsensor Measurements of Sulfate Reduction and Sulfide Oxidation in Compact Microbial Communities of Aerobic Biofilms
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DOI：
10.1128/aem.58.4.1164-1174.1992
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发表时间：
1992-04
影响因子：
4.4
通讯作者：
M. Kühl;B. Jørgensen
中科院分区：
文献类型：
--
作者：
M. Kühl;B. Jørgensen
采用O2、S2-和pH的微传感器，在高空间分辨率（25 ~ 100 μm）下测量了滴滤生物膜中O2呼吸、H2S氧化和SO 42-还原的浓度分布，并利用简单的一维扩散反应模型计算了比反应速率。电子受体和电子供体的呼吸过程和它们的反应速率的microzonation的可用性的重要性进行了研究。氧呼吸被发现在上0.2至0.4毫米的生物膜，而硫酸盐还原发生在更深的，缺氧的部分生物膜。硫酸盐还原占生物膜中有机碳总矿化量的50%。硫酸盐还原产生的H2S在狭窄的反应区内被O2再氧化，没有H2S逃逸到上覆水中。由于细菌快速氧化H2S，反应区中H2S和O2的周转时间仅为几秒钟。在培养基中添加硝酸盐可以诱导H2S与NO3-的厌氧氧化。总硫酸盐还原率增加时，SO 42-或有机基质的可用性增加，作为一个结果，加深硫酸盐还原区或硫酸盐还原强度的增加，分别。
The microzonation of O2 respiration, H2S oxidation, and SO42- reduction in aerobic trickling-filter biofilms was studied by measuring concentration profiles at high spatial resolution (25 to 100 μm) with microsensors for O2, S2-, and pH. Specific reaction rates were calculated from measured concentration profiles by using a simple one-dimensional diffusion reaction model. The importance of electron acceptor and electron donor availability for the microzonation of respiratory processes and their reaction rates was investigated. Oxygen respiration was found in the upper 0.2 to 0.4 mm of the biofilm, whereas sulfate reduction occurred in deeper, anoxic parts of the biofilm. Sulfate reduction accounted for up to 50% of the total mineralization of organic carbon in the biofilms. All H2S produced from sulfate reduction was reoxidized by O2 in a narrow reaction zone, and no H2S escaped to the overlying water. Turnover times of H2S and O2 in the reaction zone were only a few seconds owing to rapid bacterial H2S oxidation. Anaerobic H2S oxidation with NO3- could be induced by addition of nitrate to the medium. Total sulfate reduction rates increased when the availability of SO42- or organic substrate increased as a result of deepening of the sulfate reduction zone or an increase in the sulfate reduction intensity, respectively.