Pycnoporus coccineus is a widely-distributed white rot fungus in countries bordering the Indian and Pacific Oceans. It grows in broad-leaved and coniferous trees. It is commonly called orange bracket or scarlet bracket, after its brightly-hued fruiting body. This fruiting body, termed a conk, is firm, fan-shaped, and variably-sized. As you can see from today’s photo, the conk attaches itself along the straight edge of the wood. Juvenile conks begin small and bright scarlet, but their surface colour fades as they grow. One other way to identify a fungus is by the colour of its spores. In order to obtain this information, the spore-producing surface is set onto a piece of paper for several hours until it produces a spore print. Pycnoporus coccineus yields a white spore print.
Scarlet bracket digests wood, causing the wood to rot by degrading the wood’s lignin (the structural material in trees and other vascular plants). It is able to do this through the production of laccase, an enzyme with the capability of breaking down lignin and other complex organic molecules. Laccase-producing white rot fungi have gained much interest in the field of biotechnology. The article, Fungal Laccases and Their Applications in Bioremediation (2014) discusses many potential uses for laccase. It has potential abilities that include the transformation of lignin-rich feedstocks (basically, woody material) into biofuels, the removal of colour for the textile and hair dye industry, and the treatment of effluent for municipal and industrial waste.
One of the applications for white rot fungi that I find the most interesting is their ability to break down organic pollutants such as PAHs (polycyclic aromatic hydrocarbons) and chlorophenols. Many contaminated sites have high levels of these types of potentially carcinogenic pollutants. One method for treating such sites is to inoculate the soil with fungi such as Pycnoporus coccineus. The fungi chosen must not only be able to break down the contaminants found on the site, but must be able to survive in the soil long enough to complete the task. Matsubara et. al. (2006) studied many different white rot fungi, and found that scarlet bracket was able to degrade 65-80% of the PAH phenanthrene after 28 days. However, Pycnoporus coccineus was out-competed by a fungus that does not break down PAHs, Trichoderma harzianum. The authors found that two other species of white rot fungus, Schizophyllum commune and Pleurotus ostreatus were both competitive with other fungi and able to break down the contaminants that were studied. These species, as well as the employment of different inoculation substrates, were deemed worthy of further study.