By Yu Kiu Victor Chan
There is no question that the textiles industry is highly unsustainable. Production and processing of common textiles, such as cotton, harms the environment by consuming enormous amounts of fresh water, as well as creating water pollution and increasing soil acidity. Depending on where the cotton is grown, one kilogram of cotton – equivalent to the weight of a shirt and a pair of jeans – can take as much as 10,000-20,000 litres of water to produce. Petroleum-based synthetic fibres such as polyester contribute to climate change by emission of greenhouse gasses. It is estimated that textile production produces 1.2 billion tons of CO2 equivalent per year, which is more than international flights and maritime shipping combined. Hence, a sustainable textile alternative is in demand to save the planet. In recent years, a new class of synthetics called bio-textiles have been developed. This term refers to synthetic textiles made from techniques of biotechnology and bioengineering. This review aims to introduce the current development of bio-textiles and its impacts on the textile industry (Fixing fashion: clothing consumption and sustainability, 2019).
Have you wondered what it takes to produce a leather bag? It takes years to raise cattle, while it consumes food, water and produces tons of greenhouse gases. Eventually, it is slaughtered, and its skin is processed with chemicals and produced into a bag. What if this process can be shortened into weeks, and with just air, water and bits of sawdust and scraps of wood? In fact, such technology already exists, and some products have been made commercial. Biotechnology companies are now competing in the market of sustainable bio-textiles. Different types of clothing material alternatives such as leather and textiles are produced, inspired by natural materials like fungal mycelium and spider silk.
Mycelium is a natural substance that forms the vegetative part of fungi. Due to its entangled and branched network of micro-filaments called hypha, mycelium has a unique fibrous structure. Composed of chitin, glucans, mannoproteins and hydrophobins, the cell wall of mycelium provides its mechanical strength. It has been reported that mycelium material presents tunable and well-controlled structural and mechanical properties during growth, making it a versatile material. Moreover, the fibrous mycelium material shows highly hydrophobic character, which is desirable as a clothing material. Since it presents such properties, companies such as Bolt Threads and MycoWorks have been producing sustainable leather from fungal mycelium. Collaborating with big brands such as Stella McCartney, Bolt Threads will be launching products in 2021, made with Mylo™, their leather material alternative (Haneef et al., 2017).
20% of industrial water pollution globally is attributable to dyeing and treatment of textiles (Fixing fashion: clothing consumption and sustainability, 2019). Is it possible to dye textiles without contaminating our water resources? London-based biotechnology company Modern Synthesis have achieved this goal with genetically engineered bacteria. Scientists at Modern Synthesis engineered a “microbial weaving process” involving genetic engineering of a bacterium called K. rhaeticus (Microbial weaving – Modern Synthesis, 2021). The bacteria were engineered to express and produce nanocellulose and melanin (This is GMO. – Modern Synthesis, 2021). When the bacteria are grown within a scaffold, they produce fibres of nanocellulose which eventually become a tightly packed mesh of fibre, appearing as a semi-transparent film (Microbial weaving – Modern Synthesis, 2021). Cellulose is a biodegradable polymer that has versatile applications as evident in nature. On a fibre level, the nanocellulose material is up to 8 times stronger than steel and stiffer than Kevlar (Microbial weaving – Modern Synthesis, 2021). Due to its strong mechanical properties, the material has been adopted by Modern Synthesis as a potential replacement for traditional sneaker material, which is usually made from petroleum-derived plastics. Moreover, this technology has eliminated the use of dye, since the bacteria also produced melanin, a natural black pigment found in hair, skin and squid ink (This is GMO. – Modern Synthesis, 2021).
Bolt Threads also adopted a similar approach of genetic engineering and applied it to genetic engineering of yeast to fabricate spider silk-inspired textile. Spider DNA encoding for silk protein was inserted into yeast cells and left to undergo fermentation. Liquid silk protein is produced after multiple steps of processing, isolation, and purification. Further processing of the liquid silk protein eventually converts them into continuous filaments of synthetic spider silk, called Microsilk™. A lightweight, strong, and most importantly biodegradable fabric, Microsilk™ has gained attention from consumers and leading brands such as adidas. With this technology, a spider silk necktie was launched in 2017 and all 50 limited-edition were sold out within minutes. In partnership with adidas, a Biofabric Tennis Dress was launched in 2019, made with a blend of Microsilk™ and cellulose fibre (Microsilk™ | Vegan Silk Inspired by Spider Silk, 2021).
Compared to traditional textiles, bio-textiles are eco-friendly by reducing carbon footprint, energy and water consumption, as well as pollution. For the benefit of the planet, bio-textiles should and eventually will transform the textiles industry by eliminating traditional textiles. However, there are certain hurdles to overcome before the massive revolution to the current industry. First, the price of bio-textiles: R&D is an expensive process, and that would be reflected by the price of bio-textiles. Traditional textiles industry sells products at a cheaper price and minimize the production cost by enjoying economies of scale, as well as allowing forced labour in the supply chain (Fixing fashion: clothing consumption and sustainability, 2019). Hence, consumers will still prefer traditional textiles over bio-textiles due to price competition. Therefore, the bio-textiles industry is actively seeking out methods to scale-up their production and reduce production cost so that its products are competitive against traditional textiles. Second, the unawareness of consumers of the environmental costs and their preferred habit presents a challenge to bio-textiles becoming the norm. Traditional textiles such as cotton or polyesters have been the mainstream of textiles of consumption for the last century. Due to lack of alternatives, consumers are often unaware of their environmental costs and continue to purchase traditional textiles. With new alternatives, consumers should be educated on the benefits of choosing bio-textiles over traditional textiles. Adoption of bio-textiles by big brands also helps with the popularization of bio-textiles.
Advancements in the field of biomaterials and genetic engineering have given rise to a range of sustainable substitutes to replace unsustainable human consumption. From meat alternatives to textile alternatives, technology in biomaterials and genetic engineering has played a central role in driving innovation. The interplay between sustainability and science will undoubtedly continue to impact our lives in the near future.
References:
Publications.parliament.uk. 2019. Fixing fashion: clothing consumption and sustainability – Environmental Audit Committee. [online] Available at: <https://publications.parliament.uk/pa/cm201719/cmselect/cmenvaud/1952/full-report.html> [Accessed 22 February 2021].
Haneef, M., Ceseracciu, L., Canale, C., Bayer, I., Heredia-Guerrero, J. and Athanassiou, A., 2017. Advanced Materials From Fungal Mycelium: Fabrication and Tuning of Physical Properties. Scientific Reports, 7(1).
Modern Synthesis. 2021. Microbial weaving – Modern Synthesis. [online] Available at: <https://modern-synthesis.com/microbial-weaving/> [Accessed 22 February 2021].
Modern Synthesis. 2021. This is GMO. – Modern Synthesis. [online] Available at: <https://modern-synthesis.com/this-is-gmo/> [Accessed 22 February 2021].
Bolt Threads. 2021. Microsilk™ | Vegan Silk Inspired by Spider Silk. [online] Available at: <https://boltthreads.com/technology/microsilk/> [Accessed 22 February 2021].
Imperial Bioscience Review 