Novel Synthetic Polymers could Lead to Greater Crop Yields for Farmers

Scientists at the University of Birmingham have invented a new method to encourage bacteria to form growth-promoting ecosystems that could be used to coat the roots of plant seedlings, which is expected to result in stronger, healthier plants, and higher crop yields in agriculture.

In nature, the roots of seedlings form mutually beneficial relationships with communities of microbes (fungi, bacteria, viruses) in soil, and exchange nutrients, allowing both the plant and the microbes to flourish. This is particularly critical in the early stages of a plant's life when the seedling is in a race against time to reach self-sufficient growth before the nutrients and energy stores in the seed run out.

Dr. Tim Overton, an applied microbiologist from the University's School of Chemical Engineering, and Dr. Francisco Fernandez-Trillo from the School of Chemistry led a team to develop novel synthetic polymers that stimulate the formation of these bacterial communities in a way that mirrors a natural process known as biofilm formation.

A biofilm is a finely orchestrated community of microbes, supported by matrix of biological polymers that forms a protective micro-environment and holds the community together.

The researchers worked jointly on a four-year project on how polymers interact with bacteria, which resulted in the synthesis of a group of acylhydrazone-based polymers.

These new polymers were designed to act as an adhesive scaffold, "seeding" the formation of a microorganism-polymer complex to initiate and expedite biofilm formation. Once the biofilm is formed, the bacteria become a self-sufficient and self-organizing community, and produce their own matrix to allow the transmission of nutrients and water, and the discharge of waste products.

The project involved Ph.D. students Pavan Adoni and Omar Huneidi, who subsequently progressed research showing the polymers aggregate bacteria, and improve biofilm formation. Critically, they also showed the process is fully reversible, and the biofilm can be dispersed by changing the environmental conditions. The results of these experiments and further studies will be published in 2022.