Metagenomics Reveals Planktonic Bacterial Community Shifts across a Natural CO ₂ Gradient in the Mediterranean Sea

Abstract

<jats:title>ABSTRACT</jats:title> <jats:p> Bacterial communities at a CO <jats:sub>2</jats:sub> vent (pH 6.7) were compared with those at control (pH 8.0) and transition sites (pH 7.6) using 16S rRNA metagenomics. <jats:italic>Firmicutes</jats:italic> and unclassified bacteria dominated across all sites, <jats:italic>Proteobacteria</jats:italic> , especially <jats:italic>Gammaproteobacteria</jats:italic> , declined, and <jats:italic>Epsilonproteobacteria</jats:italic> increased in the vent with an increase in <jats:italic>Bacteroidetes</jats:italic> at both the vent and transition sites. </jats:p>