# Natural Sources and Microbial Transformation of Marine Halogenated Pollutants

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2021 · $125,550

## Abstract

Project Summary/Abstract
Natural polybrominated organic compounds such as hydroxylated polybrominated diphenyl ethers (OH--
BDEs) and polybrominated pyrroles (PBPs) have recently emerged as chemicals of human health concern.
These natural product relatives of anthropogenic halogenated persistent organic pollutants (POPs) are
widely distributed throughout the marine food web and accumulate in seafood sources consumed by humans.
We and others have demonstrated that OH--BDEs such as 6--OH--BDE--47 (thyroid hormone receptor)
and PBPs such as tetrabromopyrrole (ryanodine receptor) are potent toxins and thus pose a potential risk to
humans. Many fundamental questions however remain about the extent of sources for these natural
organobromine molecules, how these chemicals enter and move through the marine food web, whether
changes in the climate will impact their production and accumulation, and whether humans are more or less
impacted by natural halogenated POPs versus their anthopogentic counterparts. Recent discoveries by the
Moore and Allen laboratories have rigorously established the genetic and biochemical basis for the microbial
synthesis of natural OH--BDE molecules in diverse lineages of marine bacteria. However, the global
distribution and ubiquity of these polybrominated POPs in marine biota cannot be fully explained by the
sources discovered thus far, suggesting additional biogenic sources exist and are actively contributing to OH-
-BDE and MeO--BDE accumulation in the marine food web. This information is critical to more accurately
identify trophic connections and interconversions that lead to natural PBDE accumulation in marine fish and
ultimately, human dietary exposure risks. In this project, new genetic and biochemical evidence for the
biosynthesis and biotransformation of PBDE molecules will be established for marine macroalgae, a
conspicuous but uncharacterized source of PBDE molecules in marine habitats, using transcriptome analysis
coupled with biochemical enzyme characterization. Additional microbial sources for PBDE
synthesis/transformation will be characterized by the comprehensive analysis of fish and marine-- mammal
associated microbiomes using integrated genomic and metabolomic approaches combined with experimental
microbiome enrichment reactors amended with PBDE molecules or biosynthetic substrates. The proposed
work will be undertaken jointly by the laboratories of Moore (biochemistry) and Allen (genomics) at SIO who
have a proven track record of collaboration and joint mentorship in these areas.

## Key facts

- **NIH application ID:** 10207635
- **Project number:** 5R01ES030316-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Eric Ellsworth Allen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $125,550
- **Award type:** 5
- **Project period:** 2018-09-15 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10207635

## Citation

> US National Institutes of Health, RePORTER application 10207635, Natural Sources and Microbial Transformation of Marine Halogenated Pollutants (5R01ES030316-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10207635. Licensed CC0.

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