腐殖酸对水稻土中异化铁还原的影响  

Effects of Humic Acid on Microbial Iron(Ⅲ) Reduction in Paddy Soils

作　　者：李丽[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：《西北农业学报》2008年第6期322-328,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：国家自然科学基金项目(40741005);西北农林科技大学创新团队计划

摘　　要：分别以采自吉林、天津、四川和浙江的水稻土为供试样品,采用土壤泥浆厌氧培养、土壤微生物群落厌氧培养及纯菌培养的试验方法,研究了添加黄腐酸(FA)对体系中微生物铁还原过程的影响,采用Logistic方程对Fe(Ⅲ)还原的动力学过程进行拟合,探讨了Fe(Ⅱ)最大累计量(a)、速率常数(c)、最大反应率(Vmax)及最大还原速率对应的时间(TVmax)等参数的变化特征。结果表明,在浙江和吉林水稻土泥浆中直接添加FA,对其Fe(Ⅲ)还原动力学参数的总体影响不显著,仅是Fe(Ⅱ)最大累计量(a)比对照有微弱的增加,说明添加FA对水稻土中部分晶体氧化铁的还原具有一定作用。在土壤微生物群落厌氧培养培养中,添加FA可使Fe(Ⅲ)还原的最大反速率增大,TVmax提前,Fe(Ⅲ)还原率比对照增大,说明FA对Fe(Ⅲ)还原有明显促进作用。4株具有铁还原功能的菌株中,除菌株JX-a12外,其他3菌株在添加FA后对Fe(Ⅲ)还原速率常数(c)和Vmax有明显促进作用,高浓度FA的促进作用更加明显。研究证实了FA可作为电子穿梭物质对对Fe(Ⅲ)还原过程起到促进作用。There are some soil samples respectively collected from Jilin, Tianjin, Zhejiang and Sichuan province. Through soil slurry anaerobic incubation, co-culture incubation and pure culture method, it was used to study the effect of adding FA on the microbial iron reduction. Logistic equation was used to fit the dynamic process of Fe （Ⅲ） reduction, and discussed the changes in features of the parameters, such as the largest ag gregate of Fe （Ⅱ） （a）, the rate constant （c）, the largest response rate （Vmax） and the corresponding time of the largest aggregate （Tvmax ）. The results show that the changes of Fe （Ⅲ） reduction parameters were not significant through adding FA on the JI. and ZJ paddy soil directly, only Fe （Ⅱ） the largest aggregate of （a） had a weak increase comparing to the control. It was confirmed that FA had played an important role of crystal Fe （Ⅲ） reduction in paddy soil. In co culture incubation, comparing to the control, the largest response rate （Vmax） was promoted, and the corresponding time of the largest aggregate （Tvmax） had an advance, and the rate of Fe （Ⅲ） reduction was also promoted. It was confirmed that Fe （Ⅲ） reduction was promoted obvi ously with adding FA. In pure culture incubation of 4 strains with the function of iron reduction, in addition to the strain JX-a12, the other three strains impacted significantly on Fe （Ⅲ） reduction rate constant （c） and the largest response rate （VⅢ） , and high concentrations of FA had a more obvious role in promoting Fe （Ⅲ） reduction. The results show that FA could be used as electron shuttle to promote Fe （Ⅲ） reduction.

关 键 词：电子穿梭物质 黄腐酸 纯培养 

分 类 号：S153[农业科学—土壤学]