Kidemis AG Bets on Solid-State Fermentation to Reinvent Aquaculture Feed
- Marc Violo
- 6 hours ago
- 3 min read
Swiss startup Kidemis AG is using solid-state mycelium fermentation of agricultural waste streams to produce a protein ingredient for fish feed, aiming for production volumes of up to 50,000 tonnes per year.
In controlled trials, European perch fed diets containing 10% mycelium meal achieved roughly 30% higher final body weight than controls, with no meaningful changes to fillet quality or feed conversion.
Rainbow trout trials suggest fishmeal can be replaced at up to 40% without compromising growth or feed efficiency, with field-scale and disease-challenge trials now being planned.
From Waste Stream to Fish Feed
The global aquaculture industry has long wrestled with its dependence on fishmeal, a protein source whose supply is finite and whose production carries considerable environmental baggage. Agricultural side streams, by contrast, are plentiful and largely underused. Kidemis AG, a Swiss startup, is attempting to bridge these two realities by fermenting such side streams with fungi to produce a mycelium-based protein meal suitable for fish feed.
What distinguishes the company's approach is its use of solid-state fermentation rather than the liquid fermentation that underpins most competing mycoprotein platforms. In liquid fermentation, fungi are cultivated in large tanks of nutrient-rich broth, a process that is effective but energy-intensive and capital-heavy. Solid-state fermentation, by contrast, grows fungi directly on moist solid substrates, much as mushrooms grow on straw or wood chips. The company argues this makes production considerably cheaper and more readily scalable, a claim that, if validated at industrial volumes, could give it a meaningful cost advantage over rivals. The broader potential of converting agricultural side streams into high-value fungal protein is already attracting wider scientific and commercial interest.
Perch and Trout Put the Ingredient to the Test
Kidemis conducted its initial performance trials in European perch, a commercially important freshwater species, with support from Innosuisse, Switzerland's state innovation agency. Fish were fed one of four diets over three months in a recirculating aquaculture system—a closed-loop setup that allows precise control of water quality and reduces environmental contamination. The control diet was compared against formulations containing 5%, 7.5%, and 10% mycelium meal inclusion.
The results at the highest inclusion level were notable. Fish reached a final body weight approximately 30% greater than the control group, while feed conversion ratio—a measure of how efficiently feed is turned into body mass, remained comparable. Fillet yield was likewise unchanged. A handful of minor physiological observations were recorded, including slightly elevated cholesterol and marginally darker fillet coloration at the highest inclusion rate, but none were deemed to present welfare or product quality concerns. Digestibility was not meaningfully affected at any inclusion level, suggesting the fish processed the ingredient without difficulty.
Parallel trials in rainbow trout tested the ingredient as a direct fishmeal substitute at replacement levels of 20%, 40%, and 60%. Although full analysis is ongoing, early data indicate that growth and feed efficiency held steady up to the 40% replacement threshold—a finding that, if confirmed, would position the ingredient as a credible partial replacement for one of aquaculture's most contested inputs.
The Path to Industrial Scale
Kidemis is now seeking to move beyond controlled laboratory conditions. The company is looking for partners, particularly outside Switzerland and in Asia—to run field-scale trials across additional species, including shrimp, and to investigate whether the ingredient confers functional benefits such as enhanced disease resistance. The parallels with mycelium-based aquafeed ventures elsewhere suggest growing industry appetite for fungal alternatives to conventional fish feed inputs.
The company's medium-term production target is 50,000 tonnes per year, with the CEO noting that major feed producers typically require a supplier capable of delivering at least 15,000 to 20,000 tonnes annually before a commercial relationship becomes viable. Kidemis has begun assembling an initial network of industrial and financial partners, though further investment and geographic expansion remain priorities.
Whether solid-state fermentation can deliver protein at that scale, reliably, consistently, and at a price that competes with conventional ingredients, remains to be demonstrated. The trial data so far are encouraging. The harder task of industrialisation lies ahead.
