Asparagopsis taxiformis holobiont
Metagenomic DNA was extracted from the thawed algal tissue using the kit Quick-DNA Fecal/Soil Microbe Midiprep (Zymo Research, Irvine, CA, U.S.A.). We used the recommended instructions to process samples (2.5 g per seaweed in the present study) with the exception of the bead beater phase substituted by mixing vigorously with a vortex (Scientific Industries, Bohemia, NY, U.S.A.) for 10 minutes at maximum speed to limit algal tissue breakdown and host genomic DNA contamination. At the same time, all metagenome DNA libraries were prepared using the TruSeq Nano DNA library prep workflow (Illumina, Illumina San Diego, CA, U.S.A.), following the manufacutrers instructions and sequenced on an Illumina NextSeq 500 platform to produce 2  75 bp paired-end reads.