title: song-3
design: 16S rRNA was partially amplified using the forward primer 515F (5?-GTGCCAGCMGCCGCGG-3?) and the reverse primer 907R (5?-CCGTCAATTCCTTTGAGTTT-3?).19 The PCR reaction program was as follows: 0.2?    ?of each primer and 0.2?mM dNTP, and 1.5?mM MgCl2 and 0.2?units of Taq polymerase. PCR amplification (initial denaturation at 95?   C for 2?min, and 25 cycles at 95?   C for 30?s, 55?   C for 30?s and 72?   C for 30?s, and a final extension at 72?   C for 5?min) and gel purification procedures were conducted