Fig. 2
From: High reactivity of deep biota under anthropogenic CO2 injection into basalt
Post-injection bacterial blooms based on taxonomic distribution of the 16S-rRNA gene community profile obtained from 454-pyrosequencing. The post-injection bacterial blooms are represented as a function of time in the groundwater of control well HN-01 (a) and monitoring well HN-04 (b), with colors representing different taxa. Groundwater of control well HN-01 exhibited a relatively stable bacterial community with Chlorobi, Nitrospirae, OD1 Parcubacteria and Proteobacteria as dominant community members. While broadly similar to the pre-injection community sampled from HN-01 groundwater, the HN-04 community structure was consistently different after the pure-CO2 injection. In particular, growth of Betaproteobacteria accounting for 88% of the community in March 2012, was first favored; note a bloom of Gallionellaceae related species, which were only weakly detected before the injection (similarly shown by metagenomic analysis; Supplementary Fig. 10). It was followed by Firmicutes accounting for more than 20% of the groundwater community in May 2012, hence dominating with betaproteobacterial Thiobacillus species (Supplementary Fig. 10)
