Producing biofuel at a cost
4 Jun 2013
Genetic engineers have discovered a method of producing biofuels from lignocellulose materials - using fungi.
The research, conducted at the Vienna University of Technology (VUT), found that materials such as wood waste and straw can be used to create biofuel if long cellulose and xylan chains can be broken down into sugar molecules.
The fungi are used to create the necessary enzymes which are generated by means of a specific chemical signal.
The high costs of the chemical inductor are a decisive price driver in biofuel manufacturing
However, this process is not cost-effective and the University have claimed they can manufacture genetically modified fungi capable of producing the necessary enzymes, significantly reducing the cost of producing the biofuel.
Experts from the research team stated that it is also possible to obtain biofuel from starchy plants, but this places fuel production in direct competition with food production.
“Lignocellulose from wood waste or straw is the world’s most common renewable raw material but, due to its complex structure, it is significantly more difficult to exploit than starch” explained Professor Robert Mach, from the Institute of Chemical Engineering at VUT.
The method is made possible because the Trichoderma fungus used produces enzymes capable of breaking down the cellulose and xylan chains into the necessary sugar molecules.
The fungus, however, must be stimulated using an ‘inductor’ known as disaccharide sophorose.
The University noted that the current price of pure sophorose is around 2500 euros per gram.
“The high costs of the chemical inductor are a decisive price driver in biofuel manufacturing”, noted Mach.
The University has analysed various strains of fungus, with Mach suggesting: “In one of the strains, a random mutation occurred, which stopped the chemical switch in the fungus from functioning.”
The researchers have stated that the mutated fungus will always produce the desired enzymes, even when high glucose concentrations have been reached.
As a result of the team’s analysis, they stated it is possible to identify which gene is required for this behaviour at that it has been possible to replicate in other strains of fungus.
“We have understood the mechanism of this molecular switch and, consequently, many wonderful possibilities are opening up for us”, commented project group leader Astrid Mach-Aigner.
In an effort to make the process more economically attractive, the TUV research team are testing other areas of analysis to create sustainable fuel from lignocellulose methods.
