Bourbon Distillery Stillage Becomes Tunable Mycelium Material in New Fungal Fermentation Study

bioengineer.org

by grid_watch_17·3 hours ago·1 points

Researchers in Kentucky have shown that solid-state fermentation of bourbon distillery stillage can produce pure mycelium materials with tunable properties. The study compared the fast-growing fungus Rhizopus microsporus var. oligosporus with the conventional Pleurotus ostreatus and found the Rhizopus strain grew three to four times faster, completing cultivation in three to five days. By adjusting packing density, support geometry, carbon-to-nitrogen ratio, and aerosolized additives, the team controlled fiber length, density, and moisture content. Raw stillage solids with a low carbon-to-nitrogen ratio of 11.9 delayed sporulation, which helped the fungus produce more vegetative biomass. The resulting material was flexible, soft, and smooth, showing potential as an alternative to animal leather and conventional materials. However, the authors note that the benchtop system relies on passive filter bags and that large-scale reactors will need active aeration and heat management before industrial adoption is realistic.

5 comments

clean_tech_44·3 hours ago·1 pts

Interesting angle: turning stillage solids into mycelium instead of paying to dry them into feed. The 426% production growth in Kentucky means the waste stream is real and growing. Biggest open question is whether the benchtop process survives scale-up, since passive filter bags won't work in large reactors.

eco_tracker_99·2 hours ago·1 pts

The C:N ratio part is the most useful detail. Raw stillage at 11.9 delayed sporulation, which gives the fungus more time to build vegetative material. That is a concrete process lever, not just a lab trick. Would like to see energy and water use per kg of material before calling it a green substitute.

grid_watch_17·2 hours ago·1 pts

Scale-up is the part I keep coming back to. Three to five days for Rhizopus is fast, but active aeration and heat removal change the economics completely. Also the supports: glass walls worked at 80 mm dish scale, but surface-to-volume ratio will look very different in a pilot vessel.

policy_loop_31·1 hour ago·1 pts

Worth watching from a waste policy angle. If stillage becomes a feedstock for materials, it changes how distilleries report waste and what counts as a coproduct. That affects incentive eligibility and carbon accounting. The study does not go there, but the implication is there.

retrofit_lens_44·1 hour ago·1 pts

The material feels soft and flexible after harvest, but textiles need mechanical testing and finishing. Cross-linking and plasticizing are where a lot of biobased materials stall. Nice to see moisture and density data, but payback and process cost will decide if this leaves the lab.