# Engineering the Physico-Chemical Environment to Enhance the Bioremediation of Developmental Toxicants in Sediment Fungal-Bacterial Biofilms

> **NIH NIH P42** · DUKE UNIVERSITY · 2021 · $243,062

## Abstract

Developmental toxicants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs)
and chlorophenols (e.g., pentachlorophenol - PCP) are persistent organic contaminants found at many
hazardous waste sites throughout the United States. These contaminants are of great concern because they
present high toxicological risk in terms of their potential for bioaccumulation in the food chain as well as adverse
health effects. Hydrophobic organic contaminants (HOCs) such as PAHs, PCBs and PCP are particularly
challenging to bioremediate because their chemical characteristics diminish their bioavailability to
microorganisms thereby limiting their potential for efficient biodegradation. As a result of this constraint, HOC
remediation strategies tend to focus on physical-chemical approaches consisting of either complete excavation
of contaminated media or contaminant in situ immobilization via amendment mediated sequestration which can
have significant negative long term impacts on local ecosystems. In this project, we propose an alternative
treatment approach which consists of stimulating cooperative bacterial-fungal biofilms for HOC biodegradation.
Using this approach, indigenous fungi will first be stimulated to degrade toxicants using nonspecific extracellular
enzymes and generate by-products more bioavailable to bacteria for subsequent biodegradation. While using
remediation treatment approaches based on the production of fungal extracellular enzymes is not entirely new,
the novelty of this project resides in the fact that our focus will be directed towards the promotion of indigenous
Ascomycetes associated with sediment microbial biofilms, a phylum which has not received much attention for
bioremediation. The overall objective of this project is to maximize HOC biodegradation in sediment settings by
stimulating the growth of synergistic fungal-bacterial biofilms using engineered composite organic amendments.
The general hypothesis for Project 5 is that the physico-chemical environment can be altered using
composite organic amendments to stimulate the formation of a cooperative bacterial-fungal biofilms in
which indigenous fungi produce extracellular enzymes breaking down hydrophobic contaminants into
by-products which are more readily transported into bacterial cells and broken down by indigenous
bacteria. The specific aims for this project are to: 1) Perform microbial and geochemical characterizations of
contaminated sediments for the construction of a microbial association network model; 2) Identify organic
amendments which support the growth of cooperative fungal-bacterial biofilm and maximize HOC degradation
in microcosms; 3) Engineer and test composite amendments for delivery in sediment treatment scenarios and;
4) Implement the composite amendment strategy in large-scale mesocosms as well as validate its efficiency for
HOC degradation by stimulated mixed fungal-bacterial biofilms. Ultimately, this project will create a fra...

## Key facts

- **NIH application ID:** 10144456
- **Project number:** 5P42ES010356-19
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** Claudia Kneller Gunsch
- **Activity code:** P42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $243,062
- **Award type:** 5
- **Project period:** 2000-06-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10144456

## Citation

> US National Institutes of Health, RePORTER application 10144456, Engineering the Physico-Chemical Environment to Enhance the Bioremediation of Developmental Toxicants in Sediment Fungal-Bacterial Biofilms (5P42ES010356-19). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10144456. Licensed CC0.

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