1 School of Life Sciences, University of Warwick , Coventry CV4 7AL , UK.
3 School of Engineering, Newcastle University , Newcastle NE1 7RU , UK.
J R Soc Interface. 2019 May 31;16(154):20190129. doi: 10.1098/rsif.2019.0129.
Methane-producing microbial communities are of ecological and biotechnological interest. Syntrophic interactions among sulfate reducers and aceto/hydrogenotrophic and obligate hydrogenotrophic methanogens form a key component of these communities, yet, the impact of these different syntrophic routes on methane production and their stability against sulfate availability are not well understood. Here, we construct model synthetic communities using a sulfate reducer and two types of methanogens representing different methanogenesis routes. We find that tri-cultures with both routes increase methane production by almost twofold compared to co-cultures and are stable in the absence of sulfate. With increasing sulfate, system stability and productivity decreases and does so faster in communities with aceto/hydrogenotrophic methanogens despite the continued presence of acetate. We show that this is due to a shift in the metabolism of these methanogens towards co-utilization of hydrogen with acetate. These findings indicate the important role of hydrogen dynamics in the stability and productivity of syntrophic communities.
产甲烷微生物群落具有生态和生物技术方面的重要意义。硫酸盐还原菌与乙酸/氢营养型和严格氢营养型产甲烷菌之间的共代谢相互作用是这些群落的一个关键组成部分，但这些不同共代谢途径对甲烷产生的影响及其对硫酸盐供应的稳定性尚不清楚。在这里，我们使用硫酸盐还原菌和两种代表不同产甲烷途径的产甲烷菌构建了模型合成群落。我们发现，与共培养物相比，具有两种途径的三培养物使甲烷的产生增加了近两倍，并且在没有硫酸盐的情况下是稳定的。随着硫酸盐的增加，系统的稳定性和生产力下降，并且在具有乙酸/氢营养型产甲烷菌的群落中下降得更快，尽管仍然存在乙酸。我们表明，这是由于这些产甲烷菌的代谢向与乙酸共同利用氢的方向转变所致。这些发现表明了氢动力学在共代谢群落的稳定性和生产力中的重要作用。
