Metagenome sequencing and 103 microbial genomes from ballast water and sediments

The great threaten of microbes carried by ballast water calls for figuring out the species composition of the ballast-tank microbial community, where the dark, cold, and anoxic tank environment might select special taxa. In this study, we reconstructed 103 metagenome-assembled genomes (MAGs), including 102 bacteria and one archaea from four vessels of international voyages. Of these MAGs, 60 were ‘near complete’ (completeness >90%), 34 were >80% completeness, and nine were >75% completeness. Phylogenomic analysis revealed that over 70% (n = 74) of these MAGs represented new taxa at different taxonomical levels, including one order, three families, 12 genera and 58 species. Species composition of these MAGs were most consistent with the previous reports, with the most abundant phyla were Proteobacteria (n = 69), Bacteroidota (n = 17), and Actinobacteria (n = 7). These draft genomes provided novel data of species diversity and function in ballast-tank microbial community, which will facilitate ballast water and sediments management.