Grantee Research Project Results

Bioremediation of Plastic and Rubber by Endophytic Fungi

EPA Grant Number: F13A30122
Title: Bioremediation of Plastic and Rubber by Endophytic Fungi
Investigators: Legaspi, Michelle Elaine
Institution: Yale University
EPA Project Officer: Packard, Benjamin H
Project Period: August 1, 2014 through August 1, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Fellowship - Chemistry , Academic Fellowships

Objective:

The massive and rapid accumulation of plastic and rubber waste is a problem that be ignored. While there has been an enormous boom in synthetic polymer production, methods of treating these materials after disposal have not been able to keep up. Therefore, this research is investigating alternative methods of dealing with plastic and rubber waste. Since several types of plastic and rubber contain the same chemical bonds that are found in natural plant polymers, specific attention is given to the ability of endophytes, organisms that grow symbiotically inside plants, to degrade synthetic plastic and rubber.

Approach:

The endophytic fungus Pestalotiopsis microspore has previously been identified in the degradation of the plastic polyester polyurethane. This fungus secretes a small enzyme that is responsible for plastic degradation; the study will look for unique enzymatic characteristics by comparing this enzyme to other polyester-degrading enzymes. Large collections of endophytes from Ecuador will be screened for degradation of different plastics and rubbers using visual clearance assays, staining of degradation products, gel permeation chromatography and scanning electron microscopy. This screen will include, but not be limited to, plants that produce copious amounts of latex, the starting material for natural rubber. The genomes of any potential polymer-degrading candidates will be sequenced and searched for possible novel genes that encode plastic- or rubber-degrading enzymes.

Expected Results:

Endophytes collected in the Amazon rainforest, one of the most biodiverse places on earth, are a relatively untapped source of biological and chemical diversity. In this biodiverse ecosystem, the active evolutionary race requires organisms to utilize chemical innovation in order to outcompete their rivals and survive, possibly yielding novel natural products and unique enzymatic activity. Screens from the vast collection of Ecuadorian endophytes should identify fungi that are capable of plastic and rubber degradation, potentially using unique methods of degradation or novel polymer-degrading enzymes.

Potential to Further Environmental/Human Health Protection

Since synthetic polymers can remain intact for hundreds of years and certain materials can leach toxic chemicals into the environment, plastic and rubber waste accumulation has become a global threat to the environment and human health. It is imperative to investigate practical and sustainable methods of plastic and rubber waste disposal. Investigating the bioremediation potential of endophytic fungi will lead to a better understanding of the organisms and enzymes that could be used to degrade synthetic plastic and rubber waste.

Supplemental Keywords:

biodegradation, bioremediation, fungi

Progress and Final Reports:

2015

Final