硫酸盐作为共存电子受体对微生物Fe(Ⅲ)还原过程的影响

Effect of Sulfate as a Competitive Electron Receptor on Microbial Iron-reduction Process

Fe(Ⅲ)和SO42-都是水稻土中主要的电子受体,对厌氧过程中的电子传递起着重要作用。本研究采用土壤浸提液厌氧培养和纯培养的试验方法,探讨了SO42-作为电子竞争受体对不同水稻土微生物群落和铁还原细菌的Fe(Ⅲ)还原过程的影响。土壤浸提液培养试验结果表明,添加SO42-后Fe(Ⅲ)还原受到显著的抑制,Fe(Ⅲ)反应速率随着浓度的增加而降低。随着培养时间延长,Fe(Ⅲ)还原反应依然可以进行,Fe(Ⅱ)最终累积量达到与CK2相同的水平。在利用铁还原菌的纯培养试验中,添加SO42-对供试的四株铁还原菌的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SO42-的影响。

Fe（Ⅲ） and SO42 are the primary electron receptors in the rice soil. They play an important role in the electron transfer of anaerobic process. In this study, anaerobic microorganism community culture and microorganism pure culture were used to be the research methods. The study discussed the influence of the SO4^2- as a competitive electron receptor to Fe（Ⅲ）-reduction process of different paddy soil microorganism community and iron-reduction microorganism. Shown from the culture test of the different vaccination of paddy soil extracts, after adding SO4^2- , Fe（ Ⅲ ） reduction is inhibited significantly, but with extended incubation time, Fe（Ⅲ） reduction can still progress, and ultimately the cumulant of Fe（ Ⅱ ） achieved the same level with CK2. In the vaccination of pure iron reducing bacteria culture test, the addition of SO4^2- for the four-reducing bacteria of the iron, Fe（ Ⅲ） reduction process does not produce inhibitory effect that show iron-reducing bacteria itself is not subject to the impact of sulfate.