Biopolymers Could Make Sand Fertile

(CONNECT) Researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa) and Khalifa University of Science and Technology in Abu Dhabi are working on an approach to improve soil conditions in sandy deserts. In a first step, the scientists introduced certain bacteria and fungi into the sand, which form network structures between the grains of sand and thus give them greater cohesion, according to a press release.

The team from Empa’s Cellulose and Wood Materials Laboratory and the University of Abu Dhabi hoped that this “inoculation” would cause the introduced microorganisms to form long polymer chains that would permeate the sand and result in a stronger bond. As a result, these structures are better able to store water. To test the theory, two experiments were designed. It turned out that the samples containing bacteria allowed water to seep through six times more slowly than in the sample of pure sand.

In a second approach, the researchers had cellulose-producing bacteria produce geotextiles. The mats produced in this way were layered with sand, which ultimately slowed water permeability by a factor of 28. “This approach allows us to introduce organic matter and water into the sand and stabilise it somewhat,” Gustav Nyström, head of the Cellulose and Wood Materials Laboratory and co-author of this study, is quoted as saying in the press release. "Ideally, this promotes the growth of additional microorganisms and plants, thereby initiating the process that makes the soil more stable and fertile." Blaise Tardy, a professor at Khalifa University, sees the desert in Abu Dhabi as an ideal research site: the sand is already there, and nutrients—such as sugar—can be extracted from food and municipal waste. The study was published in the journal *Carbohydrate Polymers*. ce/ww