| 摘要: |
| [目的]研究水稻土中微生物铁还原过程的温度效应,揭示不同铁还原微生物的作用机理.[方法]采用5种水稻土为供试材料,分别提取微生物群落或分离铁还原菌株;以人工合成氧化铁作为惟一电子受体.在无机盐培养体系中接种土壤浸提液或具有铁还原功能的菌株,厌氧恒温培养;通过对接种液的不同温度处理(40,50,60,70℃)、对培养温度的控制(30和50℃)以及向体系中添加AQDS,探讨温度及AQDS对氧化铁微生物还原过程的影响.[结果]将来源于吉林、天津和湖南水稻土的浸提液在40～70℃处理1 h后作为接种液.随着处理温度的升高,其Fe(II)产生量和反应速率均呈逐渐降低趋势.在30和50.C培养温度下,来源于吉林、天津和四川的3种水稻土微生物群落添加AQDS可使Fe(Ⅲ)还原的反应速率常数增加10%～288%,而温度变化的增加幅度仅为6%～17%;对分离自四川和江西水稻土中的6株铁还原菌的纯培养试验发现,菌株JX-a08的Fe(Ⅲ)最大累积量、还原速率常数、最大反应速率及铁还原率均随培养温度的升高明显增加,表明菌株JX-a08更适于在50℃下生长.[结论]于40～70℃升温处理后,来源于吉林、天津和湖南水稻土微生物群落的铁还原能力受到一定程度抑制;添加AQDS可显著增加来源于吉林、天津和四川水稻土的3种微生物群落的铁还原反应速率;在6株铁还原菌的纯培养试验中发现了1株更适于在50℃下生长的菌株. |
| 关键词: 温度 水稻土 厌氧培养 微生物的铁还原 |
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| 基金项目:国家自然科学基金，西北农林科技大学创新团队计划 |
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| Effect of temperature and AQDS on ferric oxide microorganism reduction process |
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| Abstract: |
| 【Objective】 Based on the study of the effect of temperature on ferric oxide microorganism reduction process in paddy soil,the paper gave a theoretical principle for different ferric microorganism reductions.【Method】 5 kinds of paddy soil treatments were studied,then each microorganism biocoenosis was extracted or bacterial strain was dissociated.Artificial synthesis ferric oxide was considered only electron acceptor,which inoculated soil leaching liquor or bacterial strain with reduction function in mineral salt culture system under anaerobic constant temperature condition.After different temperature treatments towards leaching liquor,temperature was controlled and AQDS added into culture system in order to discuss the effect of temperature and AQDS on ferric oxide microorganism reduction process. 【Result】 The inoculation liquor was made from leaching liquor in Jilin,Tianjin and Hunan paddy soil under 40-70 ℃ condition for 1 h,as temperature rose,the accumulation amount of Fe(Ⅱ) and reaction rate decreased gradually.After comparison of 30 and 50 ℃ treatments,AQDS were added into 3 kinds of microorganism biocoenosis from Jiling,Tianjin and Sichuan paddy soil,and it showed that AQDS could accelerate the reduction of Fe(Ⅲ) 10%-288%,meanwhile,temperature could accelerate the reduction of Fe(Ⅲ) 6%-17%.In axenic culture treatment of 6 kinds of bacterial strains from Sichuan and Jiangxi paddy soil,the maximum accumulation amount of Fe(Ⅱ) reduction rate was constant,the maximum reaction rate and ferric reduction rate of ferric strain JX-a08 all increased as temperature rose,which showed that bacterial strain JX-a08 were suitable to 50 ℃. 【Conclusion】 As temperature increased from 40 to 70 ℃,ferric reduction capacity of microorganism biocoenosis from Jilin,Tianjin and Hunan paddy soil were restrained to a certain extent.Adding AQDS could increase ferric reduction rate of microorganisms biocoenosis from Jilin,Tianjin and Sichuan paddy soil significantly.In axenic culture treatment of 6 kinds of bacterial strain experiments from Sichuan and Jiangxi paddy soil,a bacterial strain was suitable to 50 ℃. |
| Key words: temperature paddy soil anaerobic incubation ferric reduction of microorganism |
