This article was originally published in December 2023 and has since been updated to appear in the Spring 2024 issue of Microcosm.
Clothing production is a resource-intensive process.
Source: Unsplash/Marcus Winkler.
Looking good costs money. And not just money. The clothes people wear require a huge amount of energy and resources to produce. Investing in clothes that will eventually be thrown away just adds to already bulky landfills. When it comes to sustainability, the fashion industry is rather behind the times. How can we turn something environmentally dull into something amazing?
Bacteria, or bacterial cellulose (BC), is a network of carbohydrate molecules excreted by some living organisms that can be fashioned into everything from handbags to jackets. BC can be produced from organic waste and is biodegradable, making it an attractive solution to unsightly aesthetic problems. But how can these bacterial fibers be transformed into a great “fit”? And when might we see the day when we find microbially-based clothing in our favorite clothing stores?
The ugly side of fashion
The fashion industry’s backstage life is not glamorous. The process of transforming raw materials (like cotton) into the products that end up on the runway and in stores requires hundreds of thousands of tonnes of pesticides and pesticides, and millions of tonnes of fertilizers, petroleum, and chemicals. Textile production also contributes to climate change, emitting around 1.2 billion tonnes of carbon dioxide every year, roughly 10% of global greenhouse gas emissions.
Most clothing doesn’t last long in consumers’ closets. In the United States, the average person throws out an estimated 81 pounds of clothing each year, much of it worn only a few times. When these garments end up in landfills, they can leach chemicals and microplastics into the environment and waterways, causing negative impacts on people’s health and the planet.
This situation has motivated efforts to “green” clothing production, which involves using more sustainable raw materials without sacrificing the desirable characteristics of standard natural and synthetic materials (such as comfort, breathability, and flexibility)—a big challenge, but one that bacteria may be able to solve.
The beauty of bacterial cellulose
Bacterial cellulose consists of a network of glucose molecules excreted by various species of gram-negative bacteria. It is structurally similar to plant-based cellulose already used in textile production (e.g. cotton), only the fibres are thinner. In its raw state, BC looks and feels a bit like wet leather. Manufacturers grow the bacteria in containers with a culture medium and then harvest the resulting cellulose mats to produce their products (BC is usually washed and treated to remove bacteria and other impurities).
Unprocessed bacterial cellulose resembles wet leather, which when dried can be turned into products such as handbags.
Source: Choi MS, et al./Polymers, 2022.
The final texture after treatment resembles (dried) leather, but depends on the treatment method. For example, UK-based start-up Modern Synthesis grows bacteria on the framework of the threads. The BC fill the gaps and produce a uniquely structured material that feels like dry paper, similar to nylon. In fact, microbial cellulose is an incredibly flexible material that can grow in different thicknesses and textures and be dyed in different colors. It also has a large surface area, high purity, permeability, dexterity and great stability. Moreover, by modifying factors such as nutrient and oxygen supply, or by modifying the microbes themselves through genetic engineering, producers can tune the output and structure of the BC.
Sustainability of Microbial Cellulose
And there’s a “green” element, too: BC is a rapidly renewable raw material and can be produced using waste materials or alternative energy sources. Mexican biomaterials company Polybion uses fruit waste from local growers to feed BC-producing bacteria. This fruit waste typically ends up in landfills, producing methane, a potent greenhouse gas. Using waste material helps prevent the gas from contributing to climate change. It also minimizes the costs needed for expensive culture media. Researchers have fed everything from potato peels to wastewater to BC-excreting microbes.
There’s also the issue that the clothes themselves are waste. People will throw them away. That’s natural. But clothes made with BC are biodegradable, so the environmental impact is greatly reduced. Malai Eco, a South Indian company that uses local waste coconut water to produce BC and manufactures leather-like materials, says its products will decompose naturally in compost bins. BC clothes are produced using natural dyes (including dyes made from bacteria) and with fewer harmful chemicals than traditional manufacturing processes, adding to the sustainability element.
The Future of Fashion
Despite their fascinating properties, BC-based clothing still remains in the prototype realm. Polybion unveiled a BC jacket developed in collaboration with Danish fashion brand Ganni at the 2023 Global Fashion Summit. Modern Synthesis unveiled a handbag at the same event. The jacket and handbag were not for sale, but they showcased BC’s potential, as is common in the BC fashion industry. Microbial cellulose has been recognized as a raw material for years, but products made from it have yet to hit the mainstream market.
An example of clothing made from bacterial cellulose.
Source: Choi MS, et al./Polymers, 2022.
Converting bacterial waste into wearable clothing requires optimization, which will take time. For example, BC absorbs large amounts of water (i.e., it is highly hydrophilic), which may be undesirable for making clothing. Therefore, efforts to impart hydrophobicity to BC while maintaining other beneficial properties such as flexibility and durability are an important step in its development.
Even when materials are ready for consumers, scaling up production is a lengthy, iterative process that can take 15 years or more, depending on how mature the technology is and whether the supply chain can support it. This time frame seems at odds with how fast the fashion industry moves (trends come and go, then come back again in the blink of an eye). This might lead you to believe that innovations that generate a lot of buzz early on, like BC clothing, will never reach the mass consumer.
But that doesn’t mean it won’t happen. Modern Synthesis is exploring ways to scale up production of its material using existing manufacturing infrastructure. Polybion is building the world’s first facility for industrial-scale production of BC and is focused on automating the process for optimal efficiency throughout 2024. Malai is already selling pre-made items and bundles of BC material.
While there may be uncertainty about when BC clothing will be available, the implications of moving forward with production are bigger than the possibility of getting a cool jacket. With climate change looming, the U.S. has made it a priority to bolster its bioeconomy (the share of the economy based on products, services, and processes derived from biological resources such as microorganisms). Harnessing the metabolic power of bacteria to literally put clothes on people’s backs is a step in the right direction.
Apart from manufacturing clothing, bacteria are used for a variety of other purposes, such as detecting diseases and environmental pollutants. For more information, see the following articles:
