Viral diversiy within marine biofilms and their potential roles in microbially influenced corrosion

In marine environments, a wide variety of microbes exert an important influence on the corrosion of materials. Viruses are widely distributed in biofilms formed on materials and may influence the corrosion process through interactions with key corrosive microbes. However, our understanding of the viral communities within biofilms and their implications for corrosion remains notably limited. To fill this knowledge gap, we utilized 53 publicly metagenomes to investigate the ecological dynamics of viruses within biofilms on 8 different materials and their potential roles in the corrosion of materials. In biofilms, the type of materials may be the primary factor driving differences in the diversity of viral communities. Viruses within biofilms predominantly belong to Caudoviricetes, and phylogenetic analysis of Caudoviricetes and protein-sharing networks with other environments revealed the presence of numerous novel viral clades in biofilms. The presence of virus-host linkages revealed a close association between viruses and corrosive microbes in biofilms. Viruses play a key role in corrosion by modulating host corrosion-related metabolism. It was observed that viruses could enhance host resistance to metals and antibiotics via horizontal gene transfer. Furthermore, viruses can protect themselves from host antiviral systems through anti-defense systems. Overall, this work illustrates the diversity of viruses within biofilms formed on materials and the intricate interactions between viruses and corrosive microbes, revealing the potential roles of viruses in microbially influenced corrosion.