Acknowledgements
The authors wish to thank Cor Ras, Max Zomerdijk and Dirk Geerts at Delft University of Technology for their assistance in obtaining accurate stoichiometric data and designing and setting up the reactor equipment. Furthermore, we acknowledge the contribution of Udo van Dongen in performing the methane-targeted GC measurement and improving the FISH analysis, Ben Abbas for assisting in the sequencing and Miguel Mauricio-Iglesias for assistance in parameter estimation. A. Regueira would like to thank the support of the Spanish ministry of Education (FPU14/05457) and of the CRETUS Strategic Partnership for a research stay grant . A. Regueira belongs to the Galician Competitive Research Group ED431C2017/029 and to the CRETUS Strategic Partnership (ED431E 2018/01), both programs are co-funded by FEDER (EU). This work was supported by the Soenghen Institute for Anaerobic Microbiology (SIAM), SIAM gravitation grant, the Netherlands Organization for Scientific Research (024.002.002) and Spanish Ministry of Education (FPU14/05457).