Max Planck Institute for Terrestrial Microbiology, 35043, Marburg, Karl-von-Frisch-Straße 10, Germany.
Albrecht von Haller Institute of Plant Sciences, Georg August University Goettingen, Goettingen, Germany.
Environ Microbiol Rep. 2018 Feb;10(1):33-39. doi: 10.1111/1758-2229.12602. Epub 2017 Dec 15.
Several thousands of tank bromeliads per hectare of neotropical forest create a unique wetland ecosystem that emits substantial amounts of CH . Tank bromeliads growing in the forest canopy (functional type-II tank bromeliads) were found to emit more CH than tank bromeliads growing on the forest floor (functional type-I tank bromeliads) but the reasons for this difference and the underlying microbial CH -cycling processes have not been studied. Therefore, we characterized archaeal communities in bromeliad tanks of the two different functional types in a neotropical montane forest of southern Ecuador using terminal-restriction fragment length polymorphism (T-RFLP) and performed tank-slurry incubations to measure CH production potential, stable carbon isotope fractionation and pathway of CH formation. The archaeal community composition was dominated by methanogens and differed between bromeliad functional types. Hydrogenotrophic Methanomicrobiales were the dominant methanogens and hydrogenotrophic methanogenesis was the dominant methanogenic pathway among all bromeliads. The relative abundance of aceticlastic Methanosaetaceae and the relative contribution of aceticlastic methanogenesis increased in type-I tank bromeliads probably due to more oxic conditions in type-I than in type-II bromeliads leading to the previously observed lower in situ CH emissions from type-I tank bromeliads but to higher CH production potentials in type-I tank bromeliad slurries.
数千公顷热带雨林中的凤梨科植物形成了一个独特的湿地生态系统，排放大量的 CH₄。在森林冠层中生长的凤梨科植物（功能型 II 型凤梨科植物）比在森林地面上生长的凤梨科植物（功能型 I 型凤梨科植物）排放更多的 CH₄，但这种差异的原因和潜在的微生物 CH₄循环过程尚未得到研究。因此，我们使用末端限制性片段长度多态性（T-RFLP）对厄瓜多尔南部一个新热带山地森林中两种不同功能类型的凤梨科植物罐中的古菌群落进行了特征描述，并进行了罐浆培养以测量 CH₄产生潜力、稳定碳同位素分馏和 CH₄形成途径。古菌群落组成主要由产甲烷菌组成，且在不同的凤梨科植物功能类型之间存在差异。氢营养型甲烷微菌是主要的产甲烷菌，并且在所有的凤梨科植物中，氢营养型产甲烷作用是主要的产甲烷途径。在 I 型凤梨科植物中，乙酸营养型甲烷杆菌的相对丰度增加，并且乙酸营养型产甲烷作用的相对贡献增加，这可能是由于 I 型凤梨科植物比 II 型凤梨科植物中的氧气条件更多，导致之前观察到 I 型凤梨科植物的原位 CH₄排放较低，但 I 型凤梨科植物浆中的 CH₄产生潜力较高。
