Biological methanogens from bio-reactor
Total DNA of microbial communities was extracted from BM digestates applying the NucleoSpin Microbial DNA Mini kit (Macherey-Nagel GmbH & Co. KG, Dren, Germany) according to the manufacturers instructions. The RNA contamination in the DNA sample was removed by adding 1l of RNase A (10 mg/ml, ThermoFisher Scientific, Dreieich, Germany) and incubation for 1 h at room temperature. For sequencing library preparation, microbial DNA samples were purified using the Genomic DNA Clean & Concentrator Kit (Zymo Research, Irvine, CA, USA).For sequencing on the Illumina platform, 1 g of total DNA was sheared to approximately 430 bp fragments using a focused-ultrasonicator (Covaris M220, Woburn, MA, USA). Finally, the Illumina TruSeq Shotgun PCR-free Library sample preparation kit (Illumina, Eindhoven, Netherlands) was used to construct the sequencing library, which was sequenced on the Illumina MiSeq sequencer using the Illumina MiSeq Reagent Kit v3 (Illumina, Eindhoven, Netherlands), following a 2  300 indexed high output run protocol.