The response to this series of next-gen materials articles has been feverish. It seems to have flung open the doors of labs and manufacturing facilities across the globe, sending a deluge of materials innovations and technology platforms my way, which all have a role to play in replacing toxic and resource-hungry incumbent materials. As a result, this series will be extended, but today, we journey to Polybion HQ in Mexico, to unravel nature’s most elegant and effective integrated recycling and material production unit: bacteria.
Nature’s circularity solution
In a world where industrial recycling infrastructure is fragmented and ill-equipped to deliver material circularity, a solution in nature has been staring us in the face, literally, forever. Bacteria are Earth's most abundant species and simplest organisms, evolving for 3.5 billion years, surviving mass extinctions and extreme environmental swings along the way. This has made them highly resilient and efficient at conducting biochemical reactions in symbiosis with nature. Such reactions include metabolizing waste back into the building blocks of nature–no industrial infrastructure needed.
Why bacteria?
Bacteria’s simplicity as single-celled organisms makes them microscopic powerhouses that produce useful substances (including cellulose) during their natural metabolic processes. Guanajuato-based startup Polybion leverages this, adding a layer of bioengineering to re-code bacteria’s genes to orchestrate specific metabolic outputs, thereby creating new biomaterials. The first of these is a cellulose membrane, which the bacteria bio-assembles into a ‘skin’ that can be tanned and used as a leather alternative, which they call Celium®.
On the subject of leather alternatives, Mycelium, which is grown from fungi, has experienced a surge in interest, winning the favor of brands including Allbirds who are working with NFW’s Mirum, and Hermes with Mycoworks’ Fine Mycelium. So why is Polybion using bacteria instead of fungi, and what is the difference between the material outputs?
Battle of the microorganisms: bacteria v’s fungi
During a video interview with the Polybion team, co-founder and CEO Axel Gómez-Ortigoza explained “bacteria have simpler genomes and are easier to genetically engineer” than fungi. And taking nature’s lead, he added that cellulose is the most abundant (and perhaps versatile) polymer on the planet; so with bacteria producing it, the potential for scalable, modular, and high-yielding biomaterials is immense. Bacteria’s high yield is the deal-breaker, he added, offering faster scaling and more predictable, repeatable material outputs than fungi-based alternatives.
How is Celium® made?
Polybion uses local agro-industrial food and water to feed their engineered bacteria in an industrial fermentation unit. The bacteria grows the cellulose membrane on the surface of the water by consuming glucose and fructose from the food waste and polymerizing it into cellulose, which takes 20 days.
The membrane is removed and transported to a nearby tannery where it is stabilized (to halt the live decay process) and tanned using a chrome-free method that is REACH and Environmental Protection Agency (EPA) compliant. Importantly, the stabilization and tanning of Celium requires no new infrastructure, just optimized chemistry and water usage within existing tanning facilities. This entire process, from raw material to finished ‘skin’ happens within a 30-mile radius of Irapuato, in Guanajuato, Mexico.
Scaling bacterial cellulose
In December 2021 Polybion launched “the first industrial-scale, bacterial cellulose textile, biomanufacturing facility in the world”: a 14,500 sq. ft solar-powered, carbon-neutral facility. Production volumes of Celium at this pilot factory are currently 350,000 sq. ft. per year, rising to 1.1 million by Q4 2023.
Production volumes are partially dependent on locally available waste, but of this, there is no shortage (as is true of any location on the planet with both people and industrial agriculture). The fruit waste within a 30-mile radius of FOAK I (Polybion’s pilot facility) could produce 165 million sq. ft. Celium per year: equivalent to 1% of the global leather market.
During the video interview, Axel and his co-founder, CFO, and brother, Alexis Gomez-Ortigoza, forecast that the technology will scale “10X” after pilot capacity is reached in 2023, supported by licensing of the technology to drive rapid (and probably European) expansion.
Innovation-first mindset
It’s important to note that the R&D to reach this stage of production took 6 years, and was achieved with, incredibly, only €4 million ($4.4 million). This CapEx is tiny compared to similar next-gen material innovations, so how did they manage so much with so little? The brothers say this is a result of strictly prioritizing the development of the technology and focusing on science-based problem-solving, and avoiding marketing and promotional spending during development stages. Axel’s excellence in bioengineering, and Alexis’s finance background, added to the nearby leather industry knowledge and infrastructure have also helped, no doubt. A key takeaway from this interview, I believe, is the promise of ingenuity and persistence, even in the face of modest financial resources. It’s also a fair, and probably overdue, reminder that critical innovation is happening all over the globe–in every corner, in every region, and every culture.
Sustainability gains
Celium’s sustainability gains are commensurate with adopting biological processes in place of synthetic ones. Microorganisms do not require land clearing, nor do they need daily water replenishment. They are not methane emitters, in contrast to livestock, and avoid PU and PVC which cause microplastic pollution. In fact, Celium is a holistically designed biomaterial, as opposed to the vast array of plant-based and plastic based leather alternatives on the market that are composites of plant fibres and plastic polymers that rendering them marketable as ‘vegan’ but environmentally suspect.
Polybion provided some headline resource consumption figures to flesh out the impact reduction: “cowhide tanning uses approximately 30 liters of water per square foot. By comparison, the stabilization process of Celium uses about 5 liters”; Its tanning also avoids heavy metals including chrome.
Regarding up-cycling, 1,200 metric tons of fruit waste will be processed per year at maximum capacity, helping prevent around 3000 metric tons of CO2 from entering the atmosphere. Celium's carbon footprint arises wholly from transportation and logistics and stands at 0.792 kilograms of CO2eq per square foot. I balk at material impact comparisons, but to share the information they provided for context, Polybion places Celium at around half the emissions impact of animal and plastic ‘leathers’. Celium’s calculated impacts will be revealed in detail upon receipt of the final Life Cycle Assessment (LCA).
Target audience
The startup’s strategy for collaboration and expansion is to target affordable luxury and premium global brands that produce high volumes. “We are working with forward-thinking, global consumer brands across multiple sectors ranging from affordable luxury to premium and high-end” shares their Head of Communication and Culture, Gabriela Irastorza Dragonné. Their brand partners span fashion, accessories, shoe, and automotive sectors, and the technology they have developed is suitable for materials spanning food and pharma industries too.
Innovation Roadmap
With a series A funding round under their belt, led by Blue Horizon, next on Polybion’s agenda is genetically engineering bacteria strains to boost Celium’s performance, the hand feel, and overall appearance. They are pursuing recombinant materials (from organisms with recombined genetic material) never seen before by mankind, designed and grown using life’s “molecular palette”. The output? Hybrid Organic Metamaterials. Meta indeed, thanks to 3.5 billion years of nature’s wisdom combined with advanced technology and human ingenuity: perhaps the best recipe for the next generation of environmentally responsible materials.
