Poster abstracts

Poster number 18 submitted by Marissa Gittrich

Unearthing Phage-Bacteria Interactions in Model Soil Bacteria

Marissa R Gittrich (The Ohio State), Courtney M. Sanderson, Cara M. Noel, Jonathan E. Leopold, Erica Babusci (The Ohio State), Sumeyra C. Selbes, Aghiad Daboul, Olivia R. Farinas, Steven Grabiski (The Ohio State), Paul Hyman (Ashland University), Vivek K. Mutalik (Lawrence Berkeley National Laboratory)

Abstract:
Bacteriophages (phages) play a pivotal role in driving nutrient and energy cycling across various ecosystems, yet comprehensive model systems for studying phage-bacteria interactions, particularly in soil environments, are scarce. In this study, we isolated 48 double-stranded DNA phages infecting three soil-derived, plant-growth promoting rhizobacteria Klebsiella sp. M5a1 (n=24), Pseudomonas simiae (n=13), and Paraburkholderia phytofirmans (n=11). These phages were used to challenge three genome-wide loss-of-function transposon mutant libraries (RB-TnSeq). Our analysis identified 133 bacterial genes necessary for at least one phage. These genes encompass diverse functionalities, including carbon cycling, amino acid biosynthesis, global regulators, and surface proteins. Furthermore, we investigated whether these bacterial gene requirements were based on phylogenetic relatedness. Our results indicate that phages belonging to the same species and genus (>95% and >70% Average Nucleotide Identity (ANI), respectively) generally exhibited similar requirements for bacterial genes. However, there was a divergence in genetic requirements at the family level. Discrepancies in bacterial gene requirements at the family level were further scrutinized through comparative analysis of phage genomes, revealing unique genes that potentially account for these differences. Collectively, our findings lay the groundwork for developing predictive models to elucidate similarities and differences in phage infections, with implications for both environmental and therapeutic contexts.

Keywords: Phages, knockout, model soil bacteria