# Theoretical and Experimental Studies of the Population and Evolutionary Dynamics of Bacteria and Bacteriophage.

> **NIH NIH R35** · EMORY UNIVERSITY · 2023 · $7,692

## Abstract

ABSTRACT The viruses of bacteria and archaea, phage, are touted to be the most
abundant organisms on Earth, and a great deal is known about their molecular biology,
structure, and mechanisms of replication. Nevertheless there remain fundamental
unanswered or incompletely answered questions about the population biology,
ecological role, and evolution of these viruses. In this investigation we will address and
provide answers to three of these fundamental questions: 1- What are the ecological,
genetic and evolutionary conditions for lytic (virulent) phage to be maintained in and
regulate the densities of bacterial populations? 2- Under what conditions will selection
favor a temperate rather than a purely lytic mode of phage replication and
transmission? 3- Under what conditions will selection by lytic and temperate phage
favor the evolution and maintenance of CRISPR-Cas mediated adaptive immunity, rather
than envelope or other constitutive resistance mechanisms? To address these
questions, we will use mathematical and computer simulation models, the properties of
which will be analyzed numerically with parameters estimated in the experimental
systems that will be employed for population dynamic and evolutionary experiments.
We will test the predictions (hypotheses) generated from our analysis of these models
in populations of bacteria and phage maintained in liquid, surface, and semisolid
culture. Based on the results of these experiments, we will modify our models to make
them more realistic. The experiments will be done with Escherichia coli, Pseudomonas
aeruginosa, Pseudomonas syringae, and Staphylococcus aureus and their lytic and/or
temperate phage. In addition to their importance to academic ecology, population and
evolutionary biology, the results of this basic science study may well have practical
utility. This investigation will provide an empirically supported theory that could be used
to facilitate the design and evaluation of programs to use phage for the treatment of
bacterial infections in humans and domestic animals, and to control outbreaks of
pathogenic bacteria in crops.

## Key facts

- **NIH application ID:** 10813419
- **Project number:** 3R35GM136407-04S1
- **Recipient organization:** EMORY UNIVERSITY
- **Principal Investigator:** Bruce Richard Levin
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $7,692
- **Award type:** 3
- **Project period:** 2023-06-01 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10813419

## Citation

> US National Institutes of Health, RePORTER application 10813419, Theoretical and Experimental Studies of the Population and Evolutionary Dynamics of Bacteria and Bacteriophage. (3R35GM136407-04S1). Retrieved via AI Analytics 2026-05-31 from https://api.ai-analytics.org/grant/nih/10813419. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*