中文摘要：

研究不同电子受体之间的竞争关系对揭示厌氧水稻土中微生物作用导致的氧化还原过程变化机理具有重要的理论意义。本研究采用土壤泥浆厌氧培养、人工合成氧化铁体系接种土壤浸提液厌氧培养及接种铁还原菌纯培养等试验方法,通过向培养体系中添加SO24-,探讨了硫酸盐作为竞争电子受体对不同铁还原体系中Fe（Ⅲ）还原的影响。结果表明,在2种水稻土的泥浆培养过程中,Fe（Ⅲ）还原速率均随着SO24-浓度增加而降低,但Fe（Ⅱ）的最终累积量却较对照处理有明显的增加。添加硫酸盐对Fe（Ⅲ）还原速率（k）的影响表现为：石灰性水稻土〉酸性水稻土;而最终Fe（Ⅱ）累积增加率则为：酸性水稻土〉石灰性水稻土。由接种不同水稻土浸提液的培养试验看出,添加SO24-后Fe（Ⅲ）还原受到显著的抑制,但随着培养时间延长Fe（Ⅲ）还原反应依然可以进行,并且Fe（Ⅱ）累积量最终达到与CK相同的水平。在接种铁还原菌的纯培养试验中,添加SO24-对供试的4株铁还原菌的Fe（Ⅲ）还原过程并未产生抑制效应,表明铁还原菌本身并不受硫酸盐的影响。

英文摘要：

Researches on the competition between different electron acceptors have great theoretical significance in revealing the changes mechanism of redox process caused by the roles of anaerobic microbe in paddy soil. This study used slurry anaerobic culture, synthetic iron oxide system inoculated soil extracts anaerobic culture and inoculated pure iron-reducing bacteria as testing method, in addition to the training system SO^2 4, discussed the effect of sulfate as competitive electron acceptor on Fe （ Ⅲ ） reduction in different systems of iron reduction. The results showed that in the slurry cultivation process of two kinds of paddy soils, Fe（ Ⅲ ） reduction rates decreased as SO^2 4concentration increased, hut the Fe （ Ⅱ ） ultimate cumulatant compared with the control handle had increased significantly. The impact by adding sulfate for Fe（ Ⅲ） reduction rate（k ）：calcareous paddy soil〉acidic paddy soil; and eventually the cumulative increase rate of Fe（ Ⅱ ）：acidic paddy soil〉calcareous paddy soil. Shown from the culture test of the different vaccination of paddy soil extracts, after adding SO^2 4, Fe（ Ⅲ） reduction was inhibited significantly, but with extended incubation time, Fe（Ⅲ） reduction could still progress, and ultimately the cumulant of Fe（ Ⅱ ） achieved the same level with CK. In the vaccination of pure iron-reducing bacteria culture test, the addition of SO^2 4 for the four-reducing bacteria of the iron, Fe（ Ⅲ ） reduction process did not produce inhibitory effect that show iron-reducing bacteria itself was not subject to the impact of sulfate.