Deep-sea bacteriophages facilitate their host in utilizing polysaccharide

Abstract

AbstractViruses that infect bacteria (bacteriophages) are ubiquitous in the oceans and play key roles in marine ecosystems. They impact the microbial community composition and reprogram various metabolisms of host cells by the auxiliary metabolic genes (AMGs). However, whether bacteriophages are able to reprogram host polysaccharide metabolism through relevant AMGs remains unclear. Here, we found polysaccharide could effectively induce the production of different types of bacteriophages in two deep-sea Lentisphaerae strains, as well as other members belonging to the PVC (Planctomycetes-Verrucomicrobia-Chlamydia) superphylum. Through physiological assay, genomic sequencing and analysis, we found these bacteriophages were released via a chronic style and could assist their host in metabolizing polysaccharide through AMGs. Moreover, bacteriophages induced from Lentisphaerae strain WC36 by the supplement of polysaccharide could effectively assist a marine bacterium in metabolizing and utilizing polysaccharide to promote its growth. We also demonstrated for the first time that chronic phages released from Lentisphaerae strain WC36 facilitated the enrichment and cultivation of deep-sea difficult-to-culture microbes. The findings presented here, together with recent discoveries made on the reprogramming of host energy-generating metabolisms, shed light on the poorly explored marine virus-host interaction and bring us closer to understanding the potential role of viruses in marine ecosystems.