Mina Stream anaerobic arsenic enrichment culture: Arsenate Enrichment
Enrichment of anaerobic arsenate-resistant bacteria was carried out in anaerobic jar containing 100 mL of CDM medium (0.012 mM Fe2SO4, 7 mM Na2SO4, 0.0574 mM K2HPO4, 9.5 mM NaHCO3, 18.7 mM NH4Cl, 8.12 mM MgSO4, 0.457 mM CaCl2 and 44.6 mM sodium lactate as organic carbon source, pH 7.2) with 10 mM sodium arsenate. The jar was inoculated with 10 g of sediment and incubated at 28°C for seven days. After this period, genomic DNA was extracted and purified.Genomic DNA from AsV enrichment culture was extracted and purified using the PowerSoil DNA Extraction Kit (MO BIO Laboratories, USA) according to the manufacturer’s instructions. Quantification and quality of total DNA were determined by absorbance at 260 nm and 260/280 and 260/230 ratios, respectively, using a NanoDrop Spectrophotometer (NanoDrop Technologies). DNA was stored at -20°C until further processing. Illumina MiSeq platform was used to generate bacterial community taxonomic profiles. The 16S rRNA V3-V4 region was amplified by PCR using primers described by Klindworth et al. (2013), and amplicon libraries were prepared according to the manufacturer’s protocol.