Results
The quality filtered OTU matrix counted 6,687,825 reads that were clustered into 14,209 OTUs, including 9,746 OTUs reference OTUs from Bonthond et al. (Bonthond et al., 2020) and 4,463 new OTUs. Seven out of the 184 samples had less than 1000 reads after the quality filtering treatment and were excluded from downstream analyses (Table S1).
The most abundant phylum was Proteobacteria, followed by Bacteriodetes and Planctomycetes (Figure S1A). The abundance of Planctomycetes appeared to increase in the climate room (t0) and remained high with respect to abundances in the field until the last time point (t12) where their abundance was again lower. In contrast, Actinobacteria were of relative high abundance in the field and nearly disappeared in the climate room but returned to high abundance levels again at the end of the experiment. The most abundant orders were Rhodobacterales, Flavobacteriales and Alteromonadales (Figure S1B) and at the genus level, unclassified Rhodobacteraceae were the relative most abundant group (comprised of 529 OTUs), followed by the genera Paraglaciecola (23 OTUs), Altermonas (3 OTUs) and Granulosicoccus (45, Figure S1C). During the experiment, the latter three genera decreased in abundance at the end of the experiment. Instead, the Proteobacterial genus Marivita (27 OTUs) which was also more abundant in the field (tfield ) became one of the most abundant genera.