Researchers from the University of Borås in Sweden are creating products such as paper, yarn and leather derived from a bread-eating fungus.

The 100% bio-based material is produced by a fungus that researchers fed unsold grocery store bread in the lab. The bread was dried and ground into breadcrumbs and mixed with water in a reactor. The researchers then added spores of Rhizopus delemar — which are often found on decaying food.

Source: Akram Zamani

While the fungus fed on the bread, microscopic natural fibers made of chitin and chitosan were produced, accumulating on the fungus’ cell walls. Scientists collected the cells after two days, removing lipids, proteins and other byproducts that could potentially be used in food or feed. The researchers then spun a jelly-like residue, which featured fibrous cell walls, leftover from the process into a yarn appropriate for use as sutures, wound-healing textiles and even clothing.

Meanwhile, fungal cells were flattened and dried to make paper or leather-like materials. To ensure that the fungal leather in particular is flexible enough to mimic animal leather, the researchers treated the material with tree-derived tannins to soften the leather, and combined it with alkali-treated layers to strengthen the material. Additionally, the leather’s flexibility, strength and glossiness were all reportedly improved with a glycerol and a bio-based binder treatment.

Going forward, the researchers hope to use other food waste types like fruit and vegetable waste to grow the fungi.

For more on this approach, watch the video that appears courtesy of the University of Boråsor or read the article Sustainable fungal textiles and paper-like materials from food waste, which will be presented at ACS Spring 2022, a meeting of the American Chemical Society.