The study highlights that more than 400 billion liters of bioethanol could be produced from crop wastage every year.

According to the researchers, the process of converting straw and other by-products into bioethanol is currently complex and inefficient, as high temperatures and acid conditions are necessary in the glucose-release process.

This process causes the waste to breakdown into compounds which are toxic to yeast such as furfural and hydroxymethylfurfural, making fermentation difficult.

In order to overcome such problems, genetically modified yeasts must be employed in the process.

The research, however, identified five strains of naturally occurring yeasts that are resistant to the toxic compound furfural and could be used in the fermentation process.

A team of researchers have tested more than 70 strains of yeast, of which five of them were found to be resistant to the toxic compound furfural and produced the highest ethanol yield.

UEA School of Biological Sciences lead researcher Tom Clarke said: "Dwindling oil reserves and the need to develop motor fuels with a smaller carbon footprint has led to the explosion of research into sustainable fuels.

"Bioethanol is a very attractive biofuel to the automotive industry as it mixes well with petrol and can be used in lower concentration blends in vehicles with no modifications. In Brazil, vehicles which run purely on bioethanol have been on the roads since 1979.

"Breaking down agricultural waste has previously been difficult because many strains of yeast necessary for fermentation are inhibited by compounds in the straw. Their toxic effects lead to reduced ethanol production."