Chasing the biotech rainbow
From materials to dyes, bacteria could be a new natural resource for the apparel industry. Though many of the projects under way have yet to scale up, their goal is to become as ubiquitous as enzyme finishing is today
In the beginning, indigo was derived from nature. Then came petroleum, which made it possible to obtain dyes via chemical synthesis. In the future, a number of companies, among them Pili in France, Tinctorium in the US and Colorifix in the UK, intend to produce the coveted colour by engineering nature. In this new field of research known as synthetic biology, microorganisms are being tasked with making dyes and some are even being asked to apply them directly to a fabric.
The methods used are far from new, as Marie-Sarah Adenis, Pili creative director, is quick to point out: “It is a fermentation process similar to that used to obtain fermented food and is therefore based on age-old practices that have been industrialised and thoroughly mastered.” Though simple enough on paper, the start-ups working in this field have yet to scale up the processes to meet the needs of industrial production.
In the 1990s, Palo Alto-based Genencor had investigated the possibility of making biotech dyes. It is considered a pioneer in the field of synthetic biology for industrial applications, but has since switched its focus to biofuels, and was absorbed by DuPont and may even be a part of the possible new biosciences joint venture with International Flavors &?Fragrances (IFF). It may also have been ahead of its time.
Now the pressure is on to find a better solution for a process that is essential to fashion, namely colour, and is also considered a major black spot for the industry. The World Bank estimates that the dyeing and treatment of garments is responsible for 17% to 20% of industrial water pollution globally. It is precisely this dire situation that motivated Pili to orient its biotech research towards the creation of a cleaner production method for colourants.
Carbon and sugar
The process in development at Pili, a French biotech start-up founded in 2015 and based in Toulouse, sounds simple enough as it entails feeding microorganisms sugar or other sources of carbon, which can be agricultural waste, says Ms Adenis.
The fermentation process takes place in giant vats, or bioreactors. “We control various parameters, such as temperature and oxygen levels, so as to finely orchestrate microorganism growth and production of dye molecules. Once the fermentation process is complete, we separate the dye and purify it to make it possible to apply it on textiles, like any conventional dyestuff.” The company believes that this removes a barrier to the use of its dyes, as dyeing facilities will not need to invest in new machinery. “It is key to the adoption of our technology when our first ranges of dyes will be market-ready,” she says. Pili says it can produce all shades from various types of organisms. It will nonetheless rely on classic colour fabrication, where yellow and blue are mixed to obtain green.
Pili believes its dyes will be competitive compared to their petrochemical counterparts, though scaling up is still a work in progress. “Our main challenge in the years to come is optimising the production of our microorganisms to make our colourants competitive,” says Ms Adenis. The company intends to launch industrial-scale production in 2021, and the first commercial batches would be available in 2022. In last June, it closed a new funding round, raising €3.6 million ($4m) to accelerate the development of its product portfolio from venture capital firm Elaia, private investors, business angels and existing investor SOSV. BPI France and the French State are also contributing to the financing of the company’s biotech research.
A San Francisco Bay area start-up, Tinctorium was founded in 2018 by Tammy Hsu and Michelle Zhu, a spin-off from UC Berkeley, where Ms Hsu conducted her research in synthetic biology and metabolic engineering. The company says it has identified a way to produce indigo using Escherichia coli. With the help of an enzyme, it says it can obtain indican, which is soluble in water, and the resulting dye does not need reduction. “This eliminates much of the harmful chemistry used to make indigo soluble in water,” Michelle Zhu said at a presentation during the Kingpins Catalyst Conference in Amsterdam last October.
The name of the company is derived from that of a Japanese indigo plant, the Polygonum Tinctorium, but it does not intend to stop at indigo and hopes to develop other colours. Still working on scaling up the process, the young company plans to present its first prototype dyed fabrics in this year. It would like to launch its technology with a major brand and a co-branded capsule collection before making the dyes available to all companies.
In late November last year, Colorifix, a company based in Norwich, UK, announced the launch of industrial-scale trials with a few select textile manufacturer partners, including Arvind in India, Tintex in Portugal and Forster Rohner in Switzerland.
Here again, the synthetic biology start-up feeds its organisms agricultural by-products such as sugar molasses that they turn into colourants suitable for dyeing textiles. Dr Orr Yarkoni and Dr James Ajioka, the two synthetic biologists who founded Colorifix in 2016, say they have identified the DNA that determines the specific colour of various lifeforms, be they plants or animals. This DNA is replicated and introduced into bacteria that are thus “programmed” to produce the hue. Not only do the “bugs” make the dye, they also deposit it and fix it to a textile ground—thus the company’s name Colorifix. After dyeing, the fabric is exposed to high temperatures to remove bacteria and produce a “clean” or sanitised textile. It is claimeed that one of the usual chemicals and solvents of conventional dyeing methods are necessary. The biotech bugs also operate at low temperatures, further reducing the environmental footprint of the process.
Engineered bugs
All of these companies do not readily admit, with the exception of Colorifix, that their colour-making microorganisms are genetically modified. This is not regarded as an issue, as Ms Zhu, at Tinctorium, says they are not eaten or ingested in any way.
Based in Denmark, Novozymes is a leading supplier of biotech solutions for the apparel industry and has been engineering enzymes for years to carry out various functions that help reduce water use in the apparel industry. As Ole Bille Jorgensen, in charge of technical industries marketing, tells Inside Denim, enzymes are not bacteria but a lower life form. They are used in many products, including most detergents. “Enzymes eat proteases, found in food stains. These stain removal enzymes are by far the biggest market application,” he says. “Give an enzyme water and food and it goes to work.” The company introduced two new products for denims at ITMA in 2019. Its latest denim-abrasion process, called DeniSafe, is said to allow laundries to save 90% water and reduce chemicals and energy use. A new enzyme pre-treatment process or biopreparation will reportedly enable cotton mills to obtain reliable dyeing results whilst saving 67% water, 50% energy and 50% in time, it claims.
The environmental footprint of the brewed dyes in development has been questioned. Pili says it has had a life cycle analysis conducted by an independent lab. “It says that once optimised, our process could reduce CO2 emissions tenfold and water usage fivefold. We believe our process will eliminate the need for 20 million tonnes of dangerous and toxic chemicals, such as sulphuric acid and nitric acid,” says Ms Adenis.
Ongoing experimentation
Laura Luchtman and Ilfa Siebenhaar, the Dutch fashion and textile designers that launched Living Colours in 2016, first started experimenting with bacteria for a biodesign school project. They discovered that “biodyeing” with bacteria generates little run-off, requires limited water and can be conducted at low temperatures without toxic chemicals or fixing agents. In their initial tests, they focused on the natural patterns the bacteria leave on a textile, otherwise known as stains. When they fed the bacteria specific nutriments and applied various sound frequencies, they were able to create geometric patterns and even solid colours. Further research led to a process in which the bacteria could be extracted after dyeing.
Not wanting to apply any chemical treatments, the pigments will fade in time, something that the designers do not view as a negative effect but rather as a feature that will evolve with time. The duo is pursuing its research, mostly for their own use as designers, Laura Luchtman told Inside Denim.
Though still in experimental phase, the companies working on biotech colourants seek to lay the ground for the future of dyeing. In 1905, Adolf von Baeyer won the Nobel prize for chemistry as the inventor of synthetic indigo. A century later, the market for synthetic indigo is said to represent 70,000 tonnes per year. But it requires reduction, and is said to consume 65,000 tonnes of salt yearly. Progress in synthetic biology may provide a cleaner solution to feed the indigo needs of the denim industry.
