Zymofix bets on growth

Agricultural waste streams are currently being valorised far too little. Emile Redant observed this during his career at Renasci, Biotalys, and the Bio Base Europe Pilot Plant. Just three years ago, that was the reason for Redant and his partners to establish a new company: Zymofix. ‘Initially, the plan was to upgrade biomass into a replacement for peat,’ says chief scientific officer Wendy Maddelein. ‘But agricultural waste can also serve as a growth medium for useful micro-organisms. These are normally cultivated in bioreactors, which is an expensive process. As an alternative, a solid substrate such as rice can be used. But that is less scalable and competes with the food chain.’

Zymofix uses thermal pre-treatment to transform agricultural residual streams into a usable substrate, Maddelein explains: ‘Waste streams — which could be pig manure, but also plant residues or digestate — are placed in a tank under high temperature and pressure. The resulting product resembles something like potting compost and contains many nutrients. We use this as a substrate for solid state fermentation to cultivate the desired organism.’

Closing the loop

Zymofix has deliberately started by cultivating micro-organisms with applications in agriculture, says Maddelein. ‘We select micro-organisms that we know have a useful application in agriculture. The idea is that we use a waste stream to create a beneficial product for the same sector, thereby closing the loop. Think of biostimulants that can contribute to healthier plants, or that can help plants become more stress-resistant — for instance when water or nutrients are in short supply.’ But the platform is highly flexible, she continues. ‘We have tested nearly one hundred different types of micro-organisms to date. It turns out that this method is compatible with ninety per cent of the selected types. These can also include bacteria for sectors entirely different from agriculture.’

Nor does it matter much which raw material is used. ‘Regardless of whether we use biomass or manure, the resulting substrate is suitable for cultivating micro-organisms. We are currently investigating how the type of raw material influences bacterial growth, and which micro-organisms grow best on which substrate.’ In addition, the products are being further tested for shelf life and application on various crops.

Contamination

One technical challenge is contamination during fermentation. ‘During the production of the substrate, all micro-organisms present are killed by the high temperature and pressure. We then want to produce a single type of micro-organism, but because many different nutrients are present, other species can also grow. We select fermentation conditions that are optimal for the chosen bacterium. However, one of the most important considerations is preventing contamination. Quality control is therefore of paramount importance. We keep the laboratory strictly separate from production and have stringent procedures when switching from one product to another. By carrying out each step in a controlled manner, we can obtain the desired product with a purity of 99 per cent.’

Room to breathe

The start-up was able to build on strong support, according to Maddelein. ‘We are surrounded by a powerful network. As a new entrepreneur, it is wise to seek advice from the right people. As a member of the Biotope cohort [Biotope byVIB, the Flemish Institute for Biotechnology — Ed.], we received advice on matters such as IP and legal affairs, for instance. But it is certainly also valuable to share experiences with fellow entrepreneurs.’ A familiar challenge for new businesses is funding. ‘That is why it is wonderful that we were able to receive support from Flanders through VLAIO, and from the European Innovation Council, EIC. Start-ups need time to develop ideas. Thanks to external funding, we have the breathing room to continue scaling up.’

Venture capitalists recently joined the company, giving it access to two million euros in additional investment capital. Zymofix intends to use this, amongst other things, to ramp up production. The start-up currently has two fermenters of approximately 50 litres. Before the end of this year, the company will commission a 250-litre fermenter. ‘That is an interim step towards commercial production. In 2026, we plan to begin construction of a commercial facility in Belgium. This is estimated to have a capacity of 500–1,000 tonnes per year.’