New Biomass Project: ReCHARM

  Circular economy of biogenic residues from a microbiological process chain Copyright: © TEER

In April 2023, the new biomass project ReCHARM (Recycling of Ustilago maydis Cell Debris into Biochar for Soil Amelioration) has started, which deals with the utilization of biogenic residues from a microbiological process chain.

The project aims at utilizing residues from a fermentation process that uses the biotechnological capabilities of the fungus Ustilago maydis. Both natural and heterologous products synthesized by this fungus range from bulk chemicals like itaconic acid, microbial single-cell-oil and glycolipids to expensive pharmaceutical proteins or sesquiterpenes. Moreover, due to its plant-pathogen origin, U. maydis has an extensive enzyme set to degrade plant-based substrates. One yet unsolved problem in the application of U. maydis as a versatile compound producer is its robust and thick cell wall, making it difficult to disrupt cells after cultivation and to extract intracellular products. Hence, novel strategies towards efficient cell disruption will be evaluated. To be sustainable and environmentally friendly, enzymatic approaches will be established, avoiding harsh and toxic chemicals or energy intense treatments. Furthermore, an online monitoring to evaluate the succes of the cell disruption methods will be applied.

A second bottleneck towards a sustainable and economic process is the lack of a circular process, in which culture remnants, like cell debris and unused media components, are recycled after product removal. To create a circular value chain, ReCHARM aims at processing the biomass waste stream by pyrolysis, where volatile components are degassed, and carbonaceous solids remain. These so called biochars have been promoted as a useful soil amendment with a multifunctional application. Thus, the project will combine efficient cell disruption and recycling of waste streams from U. maydis cultivations to create additional value as a key step towards completion of sustainable, circular biotechnological approaches.

The project will be led by our research assistant Alexandra Brautlacht.