Wrinkled crust (Phlebia radiata), a rot fungus found in the northern environment, has proven to be an efficient ethanol producer. In research conducted for a doctoral thesis completed at the Faculty of Agriculture and Forestry, University of Helsinki, the fungus was able to produce significant quantities of ethanol from a range of waste materials.
In addition to saw dust from different species, wrinkled crust was able to decompose straw and recycled wood waste containing a large amount of impurities. Ethanol production was particularly high when wrinkled crust was fed coreboard.
The ethanol production process is very simple, as it is based on the ability of wrinkled crust to rot wood in oxygen-free conditions and simultaneously produce ethanol. All that is needed for the process is room temperature and an airtight container where the fungus is isolated with wood material and a nutrition solution.
“Compared to commercially available methods, our process takes more time. For now, the ethanol concentrations also lag behind those produced by commercial applications. Then again, the currently available solutions are not able to utilise wood or wood waste without it first being treated with a solvent, acid or pressurised steam,” says Hans Mattila who wrote his thesis on the subject.
The process developed by University of Helsinki researchers requires no external heating, cooling or mixing, which makes it cheaper and less complicated than the commercially available techniques.
“This way, ethanol could be produced even outside the electrical grid. Utilising wrinkled crust in bioethanol production would increase flexibility and could be a more environmentally sustainable method. It could be used to produce bioethanol in a decentralised manner anywhere where wood waste is created, such as farms,” Mattila contemplates.
Further research on the method is needed before commercial production can commence. In the future, the researchers aim to modify the cultivation conditions to boost ethanol production, in addition to which uses are sought for other compounds generated in the rotting process.
“We have been investigating what else the wrinkled crust is able to produce besides ethanol. The rotting of wood produces a number of natural compounds which can increase the commercial potential of the entire process. We are currently trying to identify such compounds and their biological value.”
Hans Mattila's doctoral thesis Phlebia radiata as an ethanol producing fungus: conversion of lignocelluloses and metabolic regulation under hypoxia