pH shift-mediated dehydrogenation and hydrogen production are responsible for microbial iron(III) reduction in submerged paddy soils
pH shift-mediated dehydrogenation and hydrogen production are responsible for microbial iron(III) reduction in submerged paddy soils
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DOI：
10.1007/s11368-015-1084-8
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发表时间：
2015-02
影响因子：
3.6
通讯作者：
R. Jia;Lina Li;D. Qu
中科院分区：
文献类型：
--
作者：
R. Jia;Lina Li;D. Qu
研究了pH变化对淹水水稻土中Fe（III）[Fe（III）]还原及其脱氢和产氢的影响，以进一步了解发酵过程对微生物Fe（III）还原的贡献（Hapli-Stagnic Anthosol，HSA; pH8.14）和中国南方（Fe-Stagnic Anthosol，FSA; pH5.00）。用硫酸铝或碳酸钠将初始土壤pH调节至强酸、酸性、中性、碱性和强碱水平.Results and discussionDuring厌氧培养，当初始土壤pH变为酸性或更低水平时，脱氢酶活性（DHA）被大大抑制。然而，酸溶性Fe（III）水平的增加伴随着最大Fe（III）还原电位（a）的降低和最大Fe（III）还原速率（TVmax）的时间延长。pH值降低导致HSA中H2峰分压（ppH 2 max）显著降低，FSA增加。初始的pH值变化到中性和更高的水平没有显着的影响DHA或酸溶性铁（III），但是，ppH 2 max下降的中性治疗HSA，而TVmax略有下降，在低ppH 2的存在下，在中性至强碱性FSA。DHA与两种水稻土中Fe（III）快速还原阶段的Fe（II）积累相关（p< 0.05）。结论厌氧水稻土中DHA与微生物介导的Fe（III）还原有关。pH漂移介导的酶促脱氢和发酵产H2是淹水稻田微生物还原Fe（III）的主要动力，初始pH是主要驱动力。
PurposepH shift-induced responses of iron(III) [Fe(III)] reduction and associated dehydrogenation and hydrogen (H2) production in submerged paddy soils were investigated to improve our understanding of the contribution of fermentative processes to microbial Fe(III) reduction.Materials and methodsA 40-day anaerobic incubation experiment was conducted using two paddy soils from geographically distinct regions in northern (Hapli-Stagnic Anthosol, HSA; pH 8.14) and southern China (Fe-accumili-Stagnic Anthosol, FSA; pH 5.00), respectively. The initial soil pH was adjusted with aluminum sulfate or sodium carbonate to strongly acidic, acidic, neutral, alkaline, and strongly alkaline levels.Results and discussionDuring anaerobic incubation, as the initial soil pH shifts to acidic or lower levels, dehydrogenase activity (DHA) was greatly inhibited. However, increased acid-soluble Fe(III) level was accompanied by decreased maximum Fe(III) reduction potential (a) and prolonged time to maximum Fe(III) reduction rate (TVmax). Decreased pH led to a significantly lower peak partial pressure of H2(ppH2max) in HSA and an increase in FSA. The initial shifts in pH to neutral and higher levels had no significant effect on DHA or acid-soluble Fe(III); however,ppH2maxdeclined in the neutral treatment of HSA, whileTVmaxdecreased slightly in the presence of a low ppH2in the neutral to strongly alkaline FSA. DHA was correlated with Fe(II) accumulation in both paddy soils during the rapid Fe(III) reduction stage (p< 0.05).ConclusionsDHA is related to microbially mediated Fe(III) reduction in anaerobic paddy soils. pH shift-mediated enzymatic dehydrogenation and fermentative H2production are responsible for microbial Fe(III) reduction in flooded rice fields, with initial pH as the main driving force.