bulk.ChZ
DNA isolation and purification was performed using the MN NucleoSpin Soil kit (MN, Germany), in accordance with the manufacturers protocols. The purified DNA preparation was used as a template in the PCR reaction with universal primers to the V4 variable region of the 16S rRNA gene F515 GTGCCAGCMGCCGCGGTAA and R806 GGACTACVSGGGTATCTAAT (Bates, 2011). Sample preparation and sequencing was performed on an Illumina MiSEQ instrument (Illumina, USA) according to the manufacturer's recommendations.