Japanese biotechnology company Spiber is opening the fermentation technology behind its Brewed Protein fibers to outside manufacturers, creating a new business around the infrastructure it developed to bring its alternative textile materials to commercial scale.
The company launched Spiber Biofoundry on Oct. 2, offering strain engineering, process development and contract manufacturing services to businesses developing proteins and other fermentation-derived products. The service draws on Spiber’s research facilities in Tsuruoka, Japan, and its commercial production plant in Rayong, Thailand.
Customers can use Spiber’s technology to improve microbial protein yields, develop manufacturing processes or produce materials at volumes ranging from laboratory batches to commercial fermentation runs.
Spiber developed these capabilities over nearly two decades while commercializing Brewed Protein, a family of structural proteins produced through microbial fermentation using plant-derived sugars. The resulting materials can be processed into fibers for apparel and other applications.
That work required the company to develop expertise in gene sequence design, microbial strain construction, fermentation and protein purification. Spiber is now offering those services to outside businesses alongside its existing materials operations.
“Developing diverse structural proteins has enabled us to build the technology, expertise, and facilities needed to scale fermentation from the lab to commercial production,” said Maya Kawana, Spiber’s chief executive officer. “Through Spiber Biofoundry, we are making these capabilities available to other companies to shorten their time to market.”
The biofoundry offers two principal services. The first focuses on improving protein yields by optimizing gene sequences, introducing them into Spiber’s proprietary microbial strains and evaluating their performance.
In internal benchmarking, Spiber said its optimized sequences outperformed the original sequences for more than 90 percent of the target proteins tested. Yield improvements averaged fourfold and reached as high as 40-fold.
Separate case studies compared Spiber’s optimized sequences with commercially optimized controls. The company reported yield increases of 5.9 to 9.4 times for human fibroblast growth factor 2 and 1.1 to 2.6 times for human interferon-gamma.
Those results come from Spiber’s own testing and do not establish what customers will achieve in commercial production.
The second service covers fermentation process development, purification and contract manufacturing. Companies with an existing production strain can work with Spiber to move from laboratory testing to larger production runs.
Spiber’s Japanese research facility has fermenters ranging from 1 to 2,000 liters. Its Thailand plant is equipped with commercial fermenters holding more than 100,000 liters each.
The company said its own production strains have achieved protein concentrations of 50 grams per liter at commercial scale. That figure reflects its Brewed Protein operations rather than a guaranteed yield for outside customers.
Potential applications include research reagents, industrial enzymes, diagnostic materials and food ingredients. Spiber can also work with other fermentation products and microbial biomass.
For textile biotechnology companies, the service could provide access to industrial fermentation equipment without the upfront expense of constructing a dedicated facility. Moving from laboratory production to commercial volumes requires companies to maintain yields while controlling costs, a process Spiber has already undertaken for Brewed Protein.
Spiber says more than 40 brands have incorporated Brewed Protein into over 200 products. Three knitwear pieces from Stella McCartney’s Winter 2026 collection went on sale this fall, each combining 25 percent Brewed Protein fiber with 75 percent Responsible Wool Standard-certified wool.
The material also appeared in two designs presented during Milan Fashion Week in September as part of S|STYLE 2026 – Wardrobe Edition, a program developed in collaboration with Kering’s Material Innovation Lab.
Designer Srushti Patil used silver made entirely from Brewed Protein staple fibers with Taroni silk, while Quine Li used a Bower Roebuck fabric that mixed Brewed Protein with wool from sheep raised regeneratively in line with Kering’s production standards.
Unlike Stella McCartney’s retail knitwear, the S|STYLE pieces were presented as designer creations rather than announced commercial product launches.
Spiber has not disclosed the production volumes behind these applications or whether its Brewed Protein business is profitable. It also has not identified customers for the biofoundry service, provided revenue projections or specified how much manufacturing capacity will be available to outside companies.
The company presented the service at BioJapan 2026 in Yokohama, held Oct. 7–9. Customers can commission individual development stages or work with Spiber from strain optimization through manufacturing.
The biofoundry gives Spiber another potential use for the facilities and expertise it spent years developing for Brewed Protein. Whether contract manufacturing becomes a significant business will depend on its ability to attract customers and produce their materials at commercially viable costs.