Needle in a Whey-Stack: PhRACS as a Discovery Tool for Unknown Phage-Host Combinations

Area of Science:

• Microbiology
• Metagenomics
• Molecular Biology

Background:

• Metagenomics is crucial for microbial community analysis but lacks direct links to traditional culturing.
• Isolating specific microbial strains, especially bacteriophages and their hosts, remains challenging.
• A bottleneck exists in translating in silico metagenomic data to wet lab validation.

Purpose of the Study:

• To develop a method bridging metagenomics and culture-based isolation.
• To enable the isolation of specific phage-host pairs from complex environmental samples.
• To facilitate the realization of phageomic data potential in laboratory settings.

Main Methods:

• Exploited specific phage receptor binding protein (RBP)-host cell surface receptor interactions.
• Utilized fluorescently tagged recombinant RBPs to label specific bacterial hosts.
• Employed flow cytometry for the isolation of tagged phage-host combinations.

Main Results:

• Successfully applied the method to isolate culturable phage hosts from dairy whey and infant fecal samples.
• Demonstrated the ability to retrieve specific and viable phage-host pairs.
• Validated the PhRACS method in complex, real-world environmental matrices.

Conclusions:

• PhRACS effectively bridges the gap between in silico phageomic studies and traditional culture-based methods.
• The method allows for targeted isolation of phage-host interactions.
• PhRACS enhances the utility of metagenomic data for experimental validation and discovery.