# Project 2 - The marine microbiome as a source for the synthesis, transformation, and distribution of seafood contaminants

> **NIH NIH P01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2024 · $163,918

## Abstract

Project 2 – Summary/Abstract
Seafood is a major dietary source of diverse chemical pollutants, especially for populations who rely on seafood
as their primary protein source. Despite industrial chemicals such as PBDE fire retardants, the insecticide DDT,
and PCB lubricants being banned in the U.S. for decades due to their harm to humans and the environment,
these legacy chemicals still pose health risks due to their persistence in the ocean environment. They all share
similar chemical features of polyhalogenation that account for their toxic properties that underlie a variety of
reproductive, teratogenic, neurological, cardiovascular, and immune disease outcomes. Polyhalogenation is also
a distinctive hallmark of natural chemicals common to marine life. Natural polybrominated compounds produced
by marine bacteria and algae, such as the ubiquitous hydroxylated and methoxylated polybrominated diphenyl
ethers (OH/MeO-BDEs), polybrominated pyrroles (PBPs), and recently discovered polybrominated bis-indole
toxins, have emerged as chemicals of human health concern. 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
developmental toxins and pose potential risks to humans. Many fundamental questions remain about the extent
of sources for these natural organohalogen molecules, how these chemicals enter and move through the marine
food web, whether changes in the climate will impact their production and accumulation, and in what situations
humans may be more impacted by natural organohalogens versus their anthropogenic counterparts. Recent
discoveries by the Moore and Allen laboratories have rigorously established the genetic and biochemical basis
for the microbial synthesis of natural OH/MeO-BDE, PBP, dioxins, and bromoindole molecules in diverse
lineages of marine and aquatic bacteria. However, the global distribution and ubiquity of these molecules in
marine biota is yet to be explained by the sources thus far discovered, suggesting additional biogenic sources
exist and are actively contributing to their accumulation in marine fauna. Moreover, even less is known about
marine microbial activities that promote organohalogen biotransformation leading to degradation, detoxification,
or, potentially, the enhanced toxicity and bioaccumulation potential of modified congeners. In this Project, new
genetic and biochemical evidence for the biosynthesis and biodegradation of natural and anthropogenic
organohalogens will be leveraged to establish the diverse marine microbial communities that interact with
common marine fish seafood species. An enhanced understanding of microbial processes that contribute to the
production and breakdown of these molecules is necessary to evaluate the ecological fate of biogenic and
anthropogenic toxicants as they relate to seafood safety. The Project 2 team will engage with other Center
investigators through the bidirectional sharing...

## Key facts

- **NIH application ID:** 10733144
- **Project number:** 1P01ES035541-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Eric Ellsworth Allen
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $163,918
- **Award type:** 1
- **Project period:** 2024-03-10 → 2029-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10733144

## Citation

> US National Institutes of Health, RePORTER application 10733144, Project 2 - The marine microbiome as a source for the synthesis, transformation, and distribution of seafood contaminants (1P01ES035541-01). Retrieved via AI Analytics 2026-06-03 from https://api.ai-analytics.org/grant/nih/10733144. Licensed CC0.

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