For thousands of years, people have been using natural resources to discover dyeing colors, cleverly combining biology and the apparel industry to make a huge contribution to the development of the fashion industry. Today, factories have developed synthetic dyes containing chemicals that can be produced in large quantities for short periods of time. However, whether the colors are naturally extracted or chemically synthesized, these methods have left the fabric dyeing industry polluting and producing harmful substances that put nature in danger. However, Natsai Audrey Chieza's research on the bacteria Streptomyces Coelicolor (SC) is a natural and sustainable textile dyeing method that can perfectly solve the natural crisis.

From 7000 B.C. to the present day, natural dyes were the main way people dyed their clothes, including plants and insect dyeing. For example, people extracted yellow by boiling lichens and used mushrooms to make dyes. Eucalyptus, a tree species primarily native to Australia, produced silver and charcoal (Naturally Dyed Clothing, 2020). The first pigment in the period was indigo, extracted from the pea plant Indigofera 6,000 years ago (Zulian, 2019). Indigofera leaves do not contain indigo, so they were crushed to release a protective molecule called Indican. The molecule then reacted with oxygen and paired with another molecule to produce indigo (Zulian, 2019). In the late 1800s, German scientists discovered how to synthesize indigo with chemicals so that it could be mass-produced (The History of Fabric Dyeing, 2022). However, in the engineering process, most fabrics are colored in water, and indigo cannot be broken down in the water. Scientists needed large amounts of reducing agents to help break down the indigo and make it soluble, but reducing agents corrode pipes and destroy aquatic life (Landhuis, 2015). Additionally, the ancients used insects as dyes: the Aztecs and Mayans extracted the crimson dye from cochineal (a scale insect) that parasitized cacti, and people in the Mediterranean used snails to make royal purple (Chimileski, 2017).

Fashion has been a part of human history and is now integral to people's lives. Clothing is closely related to fashion, and the color matching of clothes is permeated into every aspect of the fashion manifestation. In the modern fast-paced society, naturally derived pigments for dyeing cloth can no longer meet the needs of the public. So, the fabric dyeing industry researches chemical substance synthetic pigments to dye and produce in large quantities within a short period of time. According to statistics, factories produce about 36,000 kg of indigo per year for dyeing blue jeans, which is approximately the weight of 6,000 African elephants (Landhuis, 2015). The industry uses more than 8,000 chemicals in various textile production processes, including dyeing and printing (Zulian, 2019). However, this makes the textile industry one of the most polluting industries. It requires large amounts of water to provide the conditions for fabric coloring. Besides, chemicals are toxic and indirectly or directly harmful to human health. After processing, fabrics usually still contain substances such as insecticides and oil-based pigments, so the chemical dyes victimize people who encounter such dyed fabrics. First, workers in textile mills or dyeing plants will eventually become victims through daily contact with toxicity through the manufacture of textiles (Zulian, 2019). Secondly, the customers wearing clothes will absorb the toxic substances through skin contact with the clothing (Zulian, 2019). In terms of the environment, the emission of factory waste materials releases toxic substances into the river water, thus polluting the water and endangering aquatic life.

Scientists continue to try to enhance the dyeing method which is harmful to the environment. Tammy Hsu and John Dueber, graduate students in bioengineering at the University of California, Berkeley, have discovered that dyeing with indican is environmentally friendly and non-polluting (Landhuis, 2015). Hsu's team extracted the protein portion of indigo plant leaves, used plant genetics to select the DNA portion that matched the enzyme, and introduced it into bacteria. The scientists put the fabric into a solution containing a cellular marker. Miraculously, after adding an enzyme, the fabric turned indigo (Landhuis, 2015). However, Thomas Bechtold, a textile chemist at the University of Innsbruck in Austria, points out that the new method still causes contamination (Zulian, 2019). When indican sugar molecules are released into the wastewater, hungry microorganisms eat the sugar and grow rapidly (Landhuis, 2015). As they absorb nutrients and develop, the microbes which need more oxygen compete with fish and other aquatic organisms for oxygen. There is also a major challenge regarding raw materials: only one gram of indican can be extracted from one liter of bacterial culture. This way, if only jeans were dyed, the industry would be buried in bacteria after a year (Landhuis, 2015).

Natsai Audrey Chieza, founder and CEO at Faber Futures, and other innovative designers have discovered a bacterium, Streptomyces coelicolor, that can directly dye textiles. Fleck says, “We make organic colors made by naturally occurring bacteria to provide a sustainable, wholesome, and environmentally friendly alternative to conventional synthetic colors” (Wien, 2021). Streptomyces is the most widely studied and well-known genus in the Actinomycetaceae family. They usually grow in the soil and play the role of decomposers. Streptomyces’ molecular structure contains many antibiotics and can synthesize antibiotics, so it has significant value in the medical field (Seipke etc, 2012). Interestingly, colonies of Streptomyces can take on many colors. When Scott Chimileski was asked to photograph the process of dyeing fabric with the bacteria, scientists soaked fabric sheets in a dilute liquid culture of Streptomyces coelicolor, and colonies formed across the plates after several days of incubation (Chimileski, 2017). SC grows fuzzy aerial mycelium and changes the fabric to red, pink, purple and blue. The bacteria dye textiles require barely any water and no chemicals. According to Natsai Audrey Chieza, “When grown directly onto textiles, the bacteria generate pigment molecules that attach themselves to fibers without chemicals and with 500 times less water than normal industrial processes” (Project Coelicolor ,2019).

To understand the importance of Streptomyces coelicolor dyeing, you must understand its dyeing mechanism and biology. There are two keys to the pattern of color that Streptomyces coelicolor can give fabric, the different growth rates of the colonies and the pigment itself. First, colonies grow at different rates in different places throughout the plate, and they even do not develop in some locations. Bacteria grow best on and closest to the medium because the colonies can directly absorb water and nutrients. However, colony formation on the fabric folds is low because the bacteria depend on the nutrients initially immersed in the fabric (Chimileski, 2017). The final color presented will vary depending on the growth of the colonies. Thus, pigment is the second key; Streptomyces coelicolor can produce pink to red prodiginine molecules (like prodigiosin) and the water-soluble molecule actinorhodin. During immersion, actinorhodin is released to the outside of the cell and its color has the pH of the environment to determine. Actinorhodin appears blue in typical laboratory cultures (Chimileski, 2017). Also, it is blue in parts lacking many cells because no red color can be detected from intracellular prodiginines. Actinorhodin shows a deep magenta color in the fabric’s flat parts with many colonies. Scientists hypothesize that this color combines the red prodiginines in the colonies with the blue actinorhodin diffusing out of the colonies. In addition to the color of Streptomyces coelicolor stain, depending on the pH of the environment, colonies can also able to change the pH of the environment, and they will form different shades of actinomycin in more acidic areas (Chimileski, 2017). Garment factories will be able to create colorful color combinations by pH. “It dyes textiles in a colourfast manner with barely any water and no chemicals,” Chieza says. “In many ways, that's the definition of a natural dye” (Coulson, 2015).

The bacterial staining method is circular, renewable and bio-based. According to Fleck: “All the processes companies do in their labs to make dyes, wasting energy and water, bacteria do in their cells, autonomously” (Wien, 2021). The dyeing process saves water resources and does not require the involvement of chemicals. Factories no longer have to use plants or insects to dye in an ecologically destructive way. Scientists also do not have to study polluting chemicals for mass production. Because bacteria proliferate, Streptomyces coelicolor achieves its goal of pure natural dyeing in short-time mass production. This discovery will revolutionize the fashion industry and improve the quality of people's lives and the environment.