# Interrogating novel biosynthetic sources for the production of polybrominated diphenyl ethers

> **NIH NIH F32** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2022 · $67,582

## Abstract

Project Summary/Abstract
 The presence of polybrominated diphenyl ethers (PBDEs) in the ocean has been a human health hazard
since their implementation as flame retardants in the 1970s, causing a myriad of toxic effects including thyroid
hormone imbalances, neurotoxicity, and developmental disorders. Since 2004, the entrance of anthropogenic
PBDEs into the environment has been limited by government restrictions on their production. However, this
environmental health crisis remains as PBDEs continue to be detected around the globe, impacting commonly
consumed seafood, marine mammals, and humans. In 2005, it was discovered that not all PBDEs are of
anthropogenic origin; commonly detected hydroxylated and methoxylated PBDEs (OH-BDEs and MeO-BDEs,
respectively) were found to be natural products. Furthermore, the toxicity of OH-BDEs and MeO-BDEs were
found to surpass that of anthropogenic PBDEs. Studies have demonstrated the persistence of PBDEs and their
hydroxylated and methoxylated congeners in the environment and their ability to be passed through the food
web; however, the handful of known OH/MeO-BDE bacterial and algal producers do not account for the global
representation of the molecules in the oceans. Here, I propose to explore the possibility of novel OH/MeO-BDE
producers by examining probable common dietary sources by searching for clues in sea water, ocean sediments,
and marine animal-associated microbiota.
 This proposal aims to mine metagenomic and metatranscriptomic data from environmental samples to
assess the distribution of OH/MeO-BDE producers in the environment and the chemistry employed in the
biosynthetic machinery. The sequences of known OH/MeO-BDE biosynthesis enzymes from marine bacteria will
be used initially as probes, followed by the use of biosynthetic logic to identify new enzymes of interest. In Aim
1, I will use this approach toward OH/MeO-BDE-producing red algae to establish, for the first time, the molecular
basis for PBDE biosynthesis in an eukaryotic system. Differential expression analysis under low and high
producing conditions will be employed to facilitate the identification of putative biosynthetic genes. In Aim 2,
known bacterial genes and newly identified eukaryotic genes will be used as probes to assess metagenomic
data from sea water, sediment, and marine animal associated microbes for the presence of PBDE biosynthesis
genes. Finally, the enzymology of PBDE biosynthetic enzymes will be explored in Aim 3 to provide a detailed
understanding of the underlying mechanisms of PBDE biosynthesis, specifically in the unique flavin dependent
halogenases responsible for aromatic decarboxylative bromination. I anticipate that this research will provide an
invaluable understanding of PBDE biosynthesis and its global distribution. Furthermore, this research will likely
facilitate studies to manage PBDE production in the environment and provide new insights into understudied
classes of enzymes.

## Key facts

- **NIH application ID:** 10471212
- **Project number:** 5F32ES033540-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** April Lukowski
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $67,582
- **Award type:** 5
- **Project period:** 2021-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10471212

## Citation

> US National Institutes of Health, RePORTER application 10471212, Interrogating novel biosynthetic sources for the production of polybrominated diphenyl ethers (5F32ES033540-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10471212. Licensed CC0.

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