What was once a niche concept is now gaining momentum as a scalable alternative to petroleum-based textiles.
Why proteins as fibers matter
Conventional fiber production, whether polyester or cotton, faces increasing scrutiny. Polyester relies on fossil fuels, while cotton demands intensive land and water use. Microbial proteins, on the other hand, provide a renewable, controllable, and biodegradable alternative. Produced in bioreactors, these proteins can be designed at the molecular level, allowing scientists to fine-tune mechanical and functional properties for performance.
- Textiles: lightweight, elastic, sustainable fabrics for fashion and performance wear.
- Medical devices: biocompatible sutures or scaffolds that integrate naturally with the human body.
- Industrial composites: resilient, bio-based materials for demanding environments
From fermentation to fabric
Strain engineering
Microbes are selected or engineered to overexpress structural proteins such as silk-like fibroins or elastin-like polypeptides. Synthetic biology tools increase yield, stability, and processability.
Controlled fermentation
Production is scaled in bioreactors, with parameters like aeration, pH, and nutrient flow tightly regulated to ensure reproducibility.
Downstream purification
Biomass is processed to isolate the target proteins. Chromatography, filtration, or precipitation steps ensure purity without denaturing functional properties.
Fiber formation
Purified proteins are transformed into fibers via extrusion or wet spinning. Alignment and cross-linking stabilize the structure, giving the fibers strength, flexibility, or specific elastic traits.
Industrial reality: from pilot to scale
The concept is not just theoretical. Japanese company Spiber has pioneered its Brewed Protein™, scaling microbial silk proteins to industrial production in its new plant in Thailand. With a capacity of ~200 tonnes per year (targeting 500), this technology has already reached the fashion industry, appearing in haute couture designs by Iris van Herpen. This demonstrates the feasibility and desirability of microbial fibers at an industrial level.
Meanwhile, microbial cellulose-based biotextiles are attracting interest for their purity, strength, and flexibility. Produced by bacteria such as Komagataeibacter xylinus, they offer high water retention and unique mechanical properties, making them attractive for both textiles and biomedical applications.
Designing for performance and circularity
Unlike petroleum-based fibers, protein-based fibers offer tunability at the sequence level. By modifying amino acid composition, researchers can influence tensile strength, elasticity, or hydrophobicity. Beyond performance, these biomaterials can be designed for end-of-life biodegradability, feeding into a circular economy.
Challenges on the road ahead
Despite their promise, challenges remain:
- Production costs: fermentation and purification processes remain expensive compared to synthetic fibers.
- Scale-up hurdles: conditions optimized at lab scale are not always reproducible in industrial bioreactors.
- Market adoption: ensuring that bio-based fibers meet performance, aesthetic, and regulatory standards.
Yet these challenges are also opportunities. They underline the need for specialized expertise in strain optimization, process control, and reproducibility: the very domains where Proventus supports its partners.
Conclusion: microbes as material makers
Microbes, once considered invisible workhorses of health and agriculture, are becoming architects of new materials. Protein-derived fibers are more than a substitute for existing textiles, they represent an entirely new class of smart, sustainable, high-performance materials.
At Proventus, we see microbial proteins as a platform technology: the same principles that produce enzymes for agriculture or bioproducts for health can be redirected toward advanced materials. By bridging biotechnology and material science, we are reshaping how the fabrics of tomorrow are designed, produced, and imagined.