design: Amplicon sequencing of D extraction negative control 4. Sequencing was performed as described in https://doi.org/10.3389/fmicb.2021.669776. {primers: GTGYCAGCMGCCGCGGTAA + GGACTACNVGGGTWTCTAAT, nucleic acid: DNA, flow cell identifier: KR96T, barcoding: UDB-H12, plate-position: 1 H10, barcodes: CAGAAATGTGTC + CAGCCTGCAAAT}.