Quality controlled read pairs (millions) Contigs N50 Accession Genome name Classification Total length (Mb) GC (%)Contigs Completeness (%) Contamination (%) Coverage (×) Protein-encoding genes (total) SAMN38186878 MP5IB2.151 Bacteria; Planctomycetia; Pirellulales; Lacipirellulaceae; Bythopirellula 4.77 56.21 204 97.63 0 42.4 4,053 SAMN38186879 MP5IB2.172 Bacteria; Bacteroidota; Bacteroidia; Chitinophagales; Saprospiraceae; JADKGY01 3.92 44.25 298 95.42 0.41 18.5 3,141 SAMN38186880 MP5IB2.194 Bacteria; Bacteroidota; Rhodothermia; Rhodother males; 5.14 62.43 304 95.9 2.19 21.4 4,229 SAMN38186881 MP5IB2.201 Bacteria; Bdellovibrionota; Bdellovibrionia; Bdellovibrio nales; SG-bin7 3.26 42.33 111 99 1.79 17.7 3,273 SAMN38186882 MP5IB2.37 Bacteria; Bacteroidota; Bacteroidia; NS11-12g; UKL13-3; B1 3.59 37.51 149 95.24 1.59 23.9 3,020 SAMN38186883 MP5IB2.67 Bacteria; Gemmatimona dota; Gemmatimonadota; Gemmatimonadales; GWC2-71-9; SZUA-320 3.29 67.18 419 95.6 2.2 27.9 3,077 SAMN38186884 MP5IB2.78 Bacteria; Planctomycetota; Planctomycetia; Planctomyce tales; Planctomycetaceae; DSVQ01 7.43 63.99 717 95.51 1.23 15.0 6,251 MP6G1 SRX3539172 101 100 223,185 4583 SAMN38186885 MP6G1.103 Bacteria; Chloroflexota; Anaerolineae; Aggregatilineales; A4b; OLB15 5.21 59.04 383 98.18 0.91 25.8 4,619 SAMN38186886 MP6G1.12 Bacteria; Planctomycetota; Phycisphaerae; Phycisphaerales; SM1A02; JAEUIT01 4.3 64.28 281 95.8 2.84 20.6 3,691 SAMN38186887 MP6G1.168 Bacteria; 4.44 61.39 335 97.27 0 28.5 4,031 (Continued on next page) using coverM (https://github.com/wwood/CoverM) and genomes were annotated using the NCBI Prokaryotic Genome Annotation Pipeline (16). Default parameters were used unless otherwise noted. Metagenomes contained 177-229 million reads which assembled into 179,000-223,000 contigs (Table 1). We retrieved 57 MAGs from 20 bacterial phyla. The median contig number for MAGs was 264. The average size and GC content were 4.296 Mb and 52.828%, respectively. Average completeness was 96.41% and contamination was 1.38%. Coverage ranged from 11.1× to 111.3×. There were 2,130-6,778 protein-encoding genes (Table 1).

These Antarctic MAGs help to remove barriers to researchers interested in the Antarctic by expanding the catalog of Antarctic bacterial genomes. They provide information that can be used to inform culturing efforts and be used in parallel with in vitro studies to understand how these organisms adapt to their extreme environment and may respond to ongoing climate change.