This study includes experiments from the following five sequencing strategies: 1) Shotgun DNA sequencing; 2) Amplicon sequencing after 18S amplification by PCR using 1391F/EukB primer set. Library were constructed according to Illumina Library protocol without any sizing; 3) Amplicon sequencing after 16S amplification by PCR using 515F/926R primer set. Library were constructed according to Illumina Library protocol without any sizing; 4) Amplicon sequencing after 16S amplification by PCR using 515F/926R primer set. Library were constructed according to Illumina Library protocol with a sizing step selecting the 450-650 bp fragments; and 5) Amplicon sequencing after 16S amplification by PCR using 515F/926R primer set. Library were constructed according to Illumina Library protocol with a sizing step selecting the 650-850 bp fragments.