Bioethanol is a biofuel for petrol engines. It is obtained by a fermentation process that converts sugar in organic matter (grain, sugar beets, sugar cane …) into alcohol. Today, bioethanol is mainly produced from glucose. If xylose (also called wood sugar) – present in the straw, willow and other fast-growing species – could also be used for ethanol production would increase by over 20% and that benefits a fuel more environmentally friendly and less expensive.

Nadia Skorupa Parachin, a doctoral candidate in microbiology at the University of Lund is on track to make this possible. The secret of his technique comes from enzymes from the garden soil. Currently, xylose, a type of sugar found in nature, is not used although it is the second most common. For ethanol production from xylose works, it is necessary to develop powerful enzymes to obtain the yeast that ferment xylose in turn. Nadia Skorupa Parachin tested these enzymes and the first results show that they bind xylose more effectively than those previously tested.

“In order that the sugars present in the forest, plants and the waste can be used to produce ethanol, yeast absorbs sugar and converts it to ethanol must have enzymes. If you just want to produce glucose The classical baker’s yeast is sufficient. However, if one wishes to convert xylose into ethanol, it is necessary to genetically modify the yeast “says Skorupa Parachin who recently patented its enzymes.

Nadia Skorupa Parachin began by extracting DNA from a soil sample that was then cut into small pieces. She was then able to establish a DNA bank. After that, she has identified the genes most suitable coupling enzyme activity and growth on xylose. Nadia Skorupa Parachin chosen to use the soil as it is an extremely diverse habitat, “a gram of soil contains ten billion bacteria! Can find enzymes and other proteins in virtually unlimited and can be all sorts Property unexplored “she exclaims. She also stresses that any soil can be used.

The reason that no researcher had already identified these new enzymes for xylose is the difficulty of the task. The thesis director Nadia Skorupa Parachin, Professor Marie-Francoise-Gorwa Grauslund, was the first person to realize that genetic engineering could walk in this context. Known as metagenomics, this method was initially used in environmental studies and it took several months to Ms. Skorupa Parachin to develop and adapt the method to this new field.

The methodology developed, researchers at Lund University will be able to apply to other areas. For example, they can adapt to isolate enzymes enable microorganisms to cope with harsh industrial conditions such as high temperatures or high concentrations of acid. Professor Gorwa-Grauslund recalls that “it is essential to have robust microorganisms if we want organic production economically viable.” It also states that “there are still a number of pieces of the puzzle that must be assembled for ethanol production from xylose is financially viable. The process must be sped up but we hope that in the long term, our method will help produce ethanol with greater efficiency.”

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