有机碳源对水稻土中微生物铁还原特征的影响  

The Effect of Organic Carbon on Microbial Iron Reduction in Paddy Soils

作　　者：宋建潇[1] 吴超[1] 曲东[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《农业环境科学学报》2013年第2期299-306,共8页Journal of Agro-Environment Science

基　　金：国家自然科学基金面上项目(40971158)

摘　　要：水稻土中的Fe(Ⅲ)还原过程是微生物介导的生物学过程,是地球化学循环中重要的一部分。为了探讨不同的电子供体对水稻土异化铁还原过程的影响,采用厌氧泥浆的培养方式,向水稻土中添加葡萄糖、乙酸钠、丙酮酸钠、乳酸钠作为碳源,定期测定Fe(Ⅱ)的累积量和pH变化,并用Logistic方程对结果进行拟合分析。结果表明,供试的4种水稻土均能较好地利用葡萄糖、丙酮酸盐和乳酸盐还原Fe(Ⅲ),而乙酸盐则不同程度的抑制了铁还原过程的发生,特别是吉林水稻土添加乙酸盐后,这种抑制作用更明显。4种水稻土添加丙酮酸盐的处理具有最大铁还原速率(Vmax),并且达到最大铁还原速率的时间(TVmax)最短。不同来源水稻土微生物在利用碳源时具有一定的选择性。影响不同水稻土铁还原潜势的主要因素是水稻土中无定形铁的含量,土壤全磷含量过高时对铁还原过程也有一定的抑制作用,添加碳源后体系pH同Fe(Ⅱ)累积量之间表现出显著负相关。As an important part of geochemistry cycles, the dissimilatory iron reduction in paddy soil is a biological process catalyzed by microorganisms. In order to study the influnce of different electron donors on microbial iron reduction in paddy soil, glucose, acetate, pyruvate and lactate was added to the anaerobic slurry of different paddy soils which were cultured under constant temperature. The accumulation of Fe(Ⅱ) and pH was monitored at regular intervals, and the test data were fitted and analyzed by Logistic model. The results showed that the four kinds of paddy soils can make good use of glucose, pyruvate and lactate to reduce Fe(Ⅲ) as carbon sources, while acetate inhibited the reduction of Fe(Ⅲ) , especially in Jilin paddy soil. The treatments with pyruvate had the maximum Fe(Ⅲ) reduction rate(V max) in all the four types of paddy soils, and took the shortest time to reach V max . Microorganisms from different paddy soil had a certain selective to carbon sources. The main factor that influences the potential capacity of reducing Fe(Ⅲ) in paddy soil is the content of amorphous iron. High content of soil total phosphorus also inhibited the process of iron reduction. Besides, there was a negative correlation between pH and the concentration of Fe(Ⅱ) in the incubation system with carbon sources.

关 键 词：水稻土 碳源 微生物铁还原 

分 类 号：X131.3[环境科学与工程—环境科学]