Syntrophobacteraceae‐affiliated species are major propionate‐degrading sulfate reducers in paddy soil
Syntrophobacteraceae‐affiliated species are major propionate‐degrading sulfate reducers in paddy soil
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DOI：
10.1111/1462-2920.13698
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发表时间：
2017-04
影响因子：
5.1
通讯作者：
Pengfei Liu;R. Conrad
中科院分区：
文献类型：
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作者：
Pengfei Liu;R. Conrad
甲烷是一种重要的温室气体，丙酸是仅次于乙酸的主要中间产物，平均占稻田甲烷碳流的23%。硫酸盐（例如，石膏）的应用可以减少CH 4排放量高达70%。然而，石膏应用对丙酸盐降解的影响和所涉及的微生物群落还没有很好地了解。因此，我们研究了丙酸盐依赖的硫酸盐还原在缺氧微宇宙的水稻土从意大利和菲律宾，结合16 S rRNA和异化亚硫酸盐还原酶（dsrB）基因图谱和共现网络分析。硫酸盐的化学计量减少丙酸除了治疗，而甲烷的生产被部分抑制。甲烷生产，但不硫酸盐还原抑制和乙酸积累后，加入甲基氟或氟乙酸。与甲基氟在硫酸盐的存在下，积累的乙酸消耗后耗尽丙酸。同时，在这两种土壤中，共生细菌科和脱硫弧菌科的相对丰度显着增强，而氟乙酸抑制脱硫菌科。石膏还显著增加了互养菌16 SrRNA和dsrB基因拷贝数。16 S rRNA和dsrB基因的网络分析说明了一个强大的共存的业务分类单位属于Syntrophobacteraceae，Desulfovibrionaceae和Desulfobulbaceae。综上所述，共生细菌科附属物种被确定为水稻土中主要的丙酸盐依赖性硫酸盐还原剂。它们（与脱硫菌科一起）将丙酸盐直接氧化为乙酸盐和CO2，或将氧化作用同养地偶联到利用H2 /甲酸盐的脱硫弧菌科。瞬时积累的乙酸优先被乙酸分解的甲烷菌科消耗。
Methane is an important greenhouse gas and propionate is next to acetate the main intermediate (average 23%) of the carbon flow to CH4 in paddy fields. Sulfate (e.g., gypsum) application can reduce CH4 emissions up to 70%. However, the effect of gypsum application on propionate degradation and the microbial communities involved are not well understood. Therefore, we studied propionate-dependent sulfate reduction in anoxic microcosms of paddy soils from Italy and the Philippines, combining 16S rRNA and dissimilatory sulfite reductase (dsrB) gene profiling and co-occurrence network analysis. Sulfate was stoichiometrically reduced in treatments with propionate addition, while CH4 production was partially suppressed. Methane production but not sulfate reduction were suppressed and acetate accumulated after addition of methyl fluoride or fluoroacetate. With methyl fluoride in the presence of sulfate, the accumulated acetate was consumed after the depletion of propionate. Simultaneously, the relative abundances of Syntrophobacteraceae and Desulfovibrionaceae were significantly enhanced, while fluoroacetate repressed Desulfobulbaceae in both soils. Syntrophobacter 16S rRNA and dsrB gene copy numbers were also remarkably increased with gypsum amendment. Network analysis of both 16S rRNA and dsrB genes illustrated a strong co-occurrence of operational taxonomic units belonging to Syntrophobacteraceae, Desulfovibrionaceae and Desulfobulbaceae. In summary, Syntrophobacteraceae affiliated species were identified as the major propionate-dependent sulfate reducers in paddy soil. They (together with Desulfobulbaceae) oxidized propionate directly to acetate and CO2 , or coupled the oxidation syntrophically to H2 /formate-utilizing Desulfovibrionaceae. The transiently accumulating acetate was preferentially consumed by acetoclastic Methanosarcinaceae.