TABLE 2.

PCR protocols used in the study, with primer sequences, hypervariable region of 16S rRNA gene amplified, and expected product size.

PCR	Primer pairs	Primer forward	Primer reverse	Region	Size (pb)	References
PCR-1	799F + 1391R	AACMGGATTAGATACCCKG	GACGGGCGGTGWGTRCA	V5–V8	600	Walker and Pace, 2007; Beckers et al., 2016; Dos Santos et al., 2017
PCR-2	967F + 1193R	CAACGCGAAGAACCTTACC	ACGTCATCCCCACCTTCC	V6–V7	230	Bodenhausen et al., 2013; Dos Santos et al., 2017
PCR-3	799F + 1193R	AACMGGATTAGATACCCKG	ACGTCATCCCCACCTTCC	V5–V7	400	Sogin et al., 2006; Walker and Pace, 2007; Beckers et al., 2016
N1PCR1*	799F + 1193R	AACMGGATTAGATACCCKG	ACGTCATCCCCACCTTCC	V5–V7	400	Sogin et al., 2006; Walker and Pace, 2007; Beckers et al., 2016
N2PCR1*	967F + 1391R	CAACGCGAAGAACCTTACC	GACGGGCGGTGWGTRCA	V6–V8	430	Walker and Pace, 2007; Callahan et al., 2016; Dos Santos et al., 2017

*N1PCR1 and N2PCR1 were nested PCRs that used as DNA template the amplification product obtained with primers 799F + 1193R (PCR1).