# Discovery of Antibiotics from Soil Microbiomes Using Metagenomics

> **NIH NIH R35** · ROCKEFELLER UNIVERSITY · 2021 · $678,000

## Abstract

Project summary: Drug-resistant infections kill more than 65,000 people in the United States per year and
the identification of new antibiotics capable of combating antibiotic resistant bacterial pathogens is desperately
needed. Bacterial natural products have a long proven history of being good lead structures for the
development of clinically useful antibiotics but, unfortunately, the discovery of novel natural products from
cultured bacteria has dramatically slowed in recent years. During the same time, the advent of cost effective
high-throughput sequencing and an increasingly sophisticated understanding of bacterial secondary metabolite
biosynthesis have led to two important revelations with respect to the search for new natural products: first,
that the biosynthetic potential of most cultured bacteria, as judged by the number of biosynthetic gene clusters
observed in sequenced genomes, is far greater than previously estimated; second, that the number of bacterial
species in most environments is at least one hundred times greater than the number of species that is readily
cultured. These observations indicate that conventional natural product screening approaches, which rely on
laboratory culturing of random bacterial strains from the environment, have not come close to realizing the full
biosynthetic potential of the earth's microbiome and that a fundamental change in the approach to bacterial
natural products discovery is therefore needed. Consequently, my laboratory has sought to develop methods
to allow natural product discovery from environmental samples, without the need for strain isolation and
cultivation. The approaches I propose to use to harvest small molecules from metagenomic libraries are
divided into two general categories: 1) Sequence-based metagenomics, which relies on DNA sequence
similarity to identify clones containing a specific gene of interest and 2) Function-based metagenomics, which
relies on the random, unbiased screening of individual eDNA clones in phenotypic assays to identify clones
producing bioactive metabolites. Using sequence-based approaches we can interrogate metagenomes for
novel gene clusters (i.e., new antibiotics), as well as clusters that encode congeners of clinically relevant
natural product (i.e., improve the utility of clinically important classes of antibiotics). Our functional screening
studies will focus on developing methods for creating metagenomic libraries that are enriched in natural
product gene clusters to facilitate more efficient screening for novel antibiotics. For this proposal, we will use
our existing pipelines and improved protocols, as they come on-line, to identify novel natural products with
improved activities against antibiotic resistant bacterial pathogens. We have undoubtedly just begun to scratch
the surface of what lies hidden in the genomes of environmental bacteria. The work here will greatly increase
access to the natural products that remain hidden in the environment ...

## Key facts

- **NIH application ID:** 10141251
- **Project number:** 5R35GM122559-05
- **Recipient organization:** ROCKEFELLER UNIVERSITY
- **Principal Investigator:** SEAN F BRADY
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $678,000
- **Award type:** 5
- **Project period:** 2017-05-01 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10141251

## Citation

> US National Institutes of Health, RePORTER application 10141251, Discovery of Antibiotics from Soil Microbiomes Using Metagenomics (5R35GM122559-05). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10141251. Licensed CC0.

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