​Scientists are inching closer to making desert soil more viable by boosting the water-holding capacity of sand exposed to constant wind erosion.

Researchers at Empa and Khalifa University of Science and Technology in Abu Dhabi found that sand reinforced with microbial biopolymer networks could slow water drainage by nearly 28-fold.

​Like plastics, biopolymers are natural long-chain molecules. These materials can be obtained from bacteria and plants.

​By binding sand grains and slowing water movement, the microbial biopolymers could help microorganisms and plants establish themselves, potentially supporting the gradual transformation of degraded land into more resilient soil.

​In this study, scientists used microbial cells that produce cellulose, a naturally occurring biopolymer made of repeating glucose units. These extremely fine thread-like structures are produced by some bacteria and plants and enhance their structural strength.  

​To test how well microbes could give sand more life, researchers used two approaches. For the first, they took sand samples collected from dunes near Al Ain in the UAE and standardized laboratory sand, then exposed the samples to microbes, including bacteria and fungi.

​To ensure that no living matter remained in the tested samples, the researchers sterilized them before introducing microbes and fresh nutrient solutions. ​

In their study, researchers used the cellulose-producing bacterium Komagataeibacter medellinensis and two strains of the fungus Schizophyllum commune. These microbes formed biopolymers that soaked the sand, creating a mesh that traps nearby particles.

​”This creates a kind of natural composite material,” said Gustav Nyström, who heads Empa’s Cellulose and Wood Materials laboratory.

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