title: metagenome of water sample: probiotics
design: Amplification of the microbial 16S rRNA V4 gene region from the extracted gDNA was performed using OneTaq 2X Master Mix (NEB, Ipswich, USA). Primer pair 515F-806R containing partial Illumina Nextera adapter in their 5' end was used to amplify the 16S V4 region (Walters et al., 2015). The polymerase chain reaction (PCR) amplification profile was as follows; Initial denaturation: 94 C for 30 s, followed by 35 cycles of denaturation (94 C for 15 s), annealing (48 C for 15 s) and extension (68 C for 30 s). The PCR products were bead-purified and subsequently indexed to incorporate dual-index barcode and Illumina adapter. The indexed PCR products were pooled, purified, and measured using Denovix high-sensitivity fluorescence quantification kit (Denovix, Delaware, USA). Single-end sequencing (300 bp  1) was performed on Illumina iSeq 100 platform (Illumina, California, USA) by GeneSEQ Sdn. Bhd. (Malaysia).