Waste Not, Want Not

David Bradley

Waste Not, Want Not

A fungus that can convert waste paper into an antibacterial and super-absorbent material has been discovered by researchers at Borås University College in Sweden. The discovery could provide a commercially and environmentally viable material for disposable diapers and sanitary wear. The products would not only have improved hygiene qualities but would be entirely biodegradable and so reduce the impact on landfill sites for these bulky products.

Iranian-born Mohammad Taherzadeh and his team began a search for a novel fungus that could be used in the biotech production of industrial ethanol for use as a gasoline additive. Within the order zygomycetes, they tested more than 100 different fungi and singled out a saprophyte, which grew extremely quickly and well on waste materials. Working with colleagues at Goteborg University, they demonstrated that the filament-producing fungus could "ferment" waste paper into ethanol and leave behind a porous and compostable residue.

"Today baker's yeast is used for the production of ethanol, but we have found a fungus that is more effective than baker's yeast," explains Taherzadeh. He adds that this fungus is "low maintenance, requiring hardly anything to start growing and degrading the waste. The temperature plays some role. We have tried to get it to grow in sulfite lye, but also in brush, forestry waste, and fruit rinds, and the results were equally good in all cases."

Being able to convert sulfite lye for the production of ethanol is good news, in both economic and environmental terms. Sulfite lye, which is a byproduct of the production of paper and viscose pulp, is difficult for factories to dispose of since it contains chemicals that must not be casually released in nature. From being a highly undesirable byproduct for the paper industry, sulfite lye will now be an attractive raw material for the extraction of ethanol.

"This is truly exciting. Zygomycetes in ethanol production represent an unknown area," Taherzadeh says, "We are the only scientists in the world to have presented them as ethanol-producing fungi, but we realize that the potential is huge"

Zygomycetes are not only highly effective in producing ethanol; the research team also found that the biomass that is left over in the production of ethanol can be used to extract a cell-wall material that is super-absorbent and antibacterial. What's more, it's a biological material that can be composted and recycled.

http://www.adm.hb.se/~mjt/