Mycelia-Assisted Isolation of Non-Host Bacteria Able to Co-Transport Phages.

Recent studies have demonstrated that phages can be co-transported with motile non-host bacteria, thereby enabling their invasion of biofilms and control of biofilm composition. Here, we developed a novel approach to isolate non-host bacteria able to co-transport phages from soil. It is based on the capability of phage-carrying non-host bacteria to move along mycelia out of soil and form colonies in plaques of their co-transported phages. The approach was tested using two model phages of differing surface hydrophobicity, i.e., hydrophobic virus T4 (T4) and hydrophilic phage HS2 (HS2). The phages were mixed into soil and allowed to be transported by soil bacteria along the mycelia of . Five phage-carrying bacterial species were isolated ( sp., sp., sp., sp., sp.). These bacteria exhibited phage adsorption efficiencies of ≈90-95% for hydrophobic T4 and 30-95% for hydrophilic HS2. The phage adsorption efficiency of sp. was ≈95% for both phages and twofold higher than T4-or HS2-adsorption to their respective hosts, qualifying sp. as a potential super carrier for phages. Our approach offers an effective and target-specific way to identify and isolate phage-carrying bacteria in natural and man-made environments.