title: replicate 3 of bacterial 16S rDNA V4 region, control treatment, in May.
design: The V4 region of the 16S rRNA gene of bacteria was amplified using the 515F/806R (5¡¯-GTGCCAGCMGCCGCGGTAA-3¡¯/5¡¯-GGACTACHVGGGTWTCTAAT-3¡¯).