Mushrooms:
Higher Macrofungi to Clean Up the Environment

Shiitakes, portabellas, criminis, oysters, whites, morels – mushrooms conjure ideas of savory sauces and gourmet meals. Battelle, however, is using these and many other higher macrofungi to clean up the environment. The technique is called mycoremediation, which uses mycelium, the vegetative part of a fungus, to break down contaminants.

Battelle staff developed a sophisticated process to condition fungal species to be more efficient at remediating particular compounds. This research led to a pending patent on the method by which proprietary strains of fungi can be developed. Battelle continually expands its library of such strains, each with unique capabilities, environmental tolerance, improved effectiveness against specific contaminants, and geographical distribution. Only species native to a site or region would be applied in the field.

Battelle research in mycoremediation is still at the testing stage, but the research is promising. Contaminants under investigation include petroleum, fertilizers, pesticides, explosives, and a wide assortment of agricultural, medical, and industrial wastes. In field applications, the natural microbial community participates with the fungi to completely break down contaminants to carbon dioxide and water. Higher wood-degrading fungi are particularly effective in breaking down aromatic pollutants, as well as chlorinated compounds. They also are natural predators and competitors of microorganisms such as bacteria, nematodes, and rotifers. Proprietary strains have been developed that detect, attack, and destroy or inhibit the growth of bacterial contaminants, such as Escherichia coli.

Although much of the recent research involving fungal remediation has focused on white-rot fungus, Battelle scientists are now using a wide variety of species representing many fungal groups, and they are exploring various fungal enzymatic mechanisms for producing beneficial byproducts.

This quiet, benign method for dealing with some of the world’s most contaminated sites has many advantages. It is completely safe, economical, involves minimal handling and maintenance, and requires no new structures to be built to process material. Macrofungi degrade compounds resistant to other biological treatments without generating secondary waste streams that require further treatment. Unpleasant odors and visual impacts are immediately mitigated by the application. The result is a beneficial, useful end-product, such as clean soil, compost, or sediment. These end-products can be used for landscaping, capping material, road-grade fill, and many other uses, including the potential for a harvestable crop. Liability is turned into an opportunity by a purely natural system.

For more information, contact Dr. Susan Thomas (360) 361-3648, sa.thomas@pnl.gov.