Biofuels from winery waste

In Australia, around 1.75 million tonnes of grapes are crushed for wine each year - and after they’re done, more than half of that is left over as biomass waste, comprising skins, pulp, stalks and seeds.

Unfortunately, most of this goes to landfill as it has little nutritional value for animal feed and can’t be composted as it doesn’t degrade.

Avinash Karpe, a PhD student at Swinburne University of Technology, has found a way to break down winery waste into compounds for use as biofuels and medicines.

“Various fungi are known to degrade this waste by generating an array of enzymes,” Karpe said. “These enzymes convert the waste to soluble sugars which can then be converted into other products.”

Using a ‘cocktail’ of four fungi - Trichoderma harzianum, Aspergillus niger, Penicillium chrysogenum and Penicillium citrinum - in a one-litre bioreactor, Karpe succeeded in breaking down the biomass, with noticeable increases in enzyme activity and lignin degradation.

The fermentation process takes one to three weeks and produces alcohols, acids and simple sugars of industrial and medicinal interest.

“We have demonstrated this technique in the laboratory, but this process can be scaled up to an industrial scale,” chair of Swinburne’s Department of Chemistry and Biotechnology, Professor Enzo Palombo, said.

Karpe’s research has been published in the Journal of Chemical Technology and Biotechnology.