DNA was extracted using a DNeasy PowerMax Soil Kit (QIAGEN, Corp., Germany), following the manufacturer's instructions.The V9 region of the eukaryotic small-subunit 18S rRNA gene was amplified using the primer set 1380F (5_CCCTGCCHTTTGTACACAC_3) and 1510R (5_CCTTCYGCAGGTTCACCTAC_3). The V3_V4 region of the bacterial 16S rRNA gene was amplified using the primer set 338F (5_ACTCCTACGGGAGGCAGCAG_3) and 806R (5_GGACTACHVGGGTWTCTAAT_3).