title: Ash addition on marine prokaryote metagenome, July 2019 T0
design: After a 48-h microcosm incubation, or before in the case of T0, the water in the three replicas of T0, control, T3, and T5 samples was mixed within each type of sample to allow for enough volume (2 L), which was filtered through 0.2-m-pore-size Sterivex filters. Subsequently, the filters were flash-frozen in liquid N2 and kept at -80C. Afterwards, DNA was extracted from the cells retained in the filters, using DNAeasy PowerWater Kit (Qiagen). DNA concentration was assessed using a Qubit 2.0 fluorometer and Qubit dsDNA HS Assay Kit (Thermo Fischer Scientific). The V4-V5 hypervariable regions of the 16S rRNA gene were Illumina sequenced, using the following primers: 515F-Y (5-GTGYCAGCMGCCGCGGTAA-3) and 926-R (5-CCGYCAATTYMTTTRAGTTT-3) (Parada et al. 2016).