Nitrate-dependent AOM biomass
The primer set 926F (5-AAACTYAAAKGAATTGACGG-3) and 1392R (5- ACGGGCGGTGTGTRC-3) were used to amplify the V6 to V8 regions of 16S rRNA gene. The sequencing was performed on the DNBSEQ-G400 platform. Raw data were filtered to obtain high-quality clean data