When considering projects for the 2022 season, one thing our iGEM team wanted to focus on was improving a problem that impacts people globally. We identified a problem in the textile industry. Synthetic dyes are cheap and easy to mass produce, making them popular with manufacturers, however, synthetic dyes have many drawbacks. They pose a potential hazard to surrounding communities in numerous ways. Azo dyes are currently the standard dye for textiles making up around 70% of all dyes used on textiles (1). Our team identified three major concerns with these dyes. First, chemical compounds found in azo dyes can be dermally absorbed into the body through consistent fabric to skin contact (5). Some of these azo dyes are confirmed mutagens and/or carcinogens (2 & 4). On top of the health risks associated with consumer exposure, the chemicals in these dyes also pose an occupational health hazard for the workers making these textiles (7). We often find that things that are bad for our health are bad for our planet’s health as well. Such is the case with azo dyes, which severely contaminates the groundwater and nearby rivers of dying facilities (1). Additionally, they are long lasting in aquatic environments, leading to decreased photosynthesis (1). Both the humanitarian and environmental impacts presented by the use of azo dyes was very apparent, so we set out to change it.
Our goal with this project was three-fold, first to make a safer and less hazardous alternative to azo dyes. Our alternative will be healthier for manufacturers and consumers while also better for the environment. We aim to accomplish this goal by using a protein-based dye that is not harmful to humans and can be broken down in aqueous environments resulting in less pollution. Our second goal is to make these alternatives economically feasible. As azo dyes are very inexpensive to use, the alternative we come up with would need to be similar or ideally lower in price to be feasible for the market to change. The third and final goal of our project is to bring awareness to the harmful use of azo dyes in the textile industry and the side effects of their use through our community outreach efforts. Azo dyes are the most widely used colorants in the textile industry, but they come with a range of negative side effects. We hope to bring awareness to these dangers and encourage people to seek out safer alternatives, while also designing economically feasible protein-based alternatives to these dyes.
While brainstorming ideas and forming our experimental design, we kept a range of ideas in mind when deciding what to focus on for this year's project. With more literature research, we discovered an extensive list of issues present in the current textile industry. Our team chose two standards that we wanted to uphold throughout the duration of the project:
With these standards in mind moving forward, we wanted to create a dye that would follow both. We met with a local industry leader, John Ballantyne, to discuss the limitations of our project and how they could be overcome or mitigated.
For feedback about our biomanufacturing process, we consulted Dr. John Ballantyne. John has his Ph.D. in pharmaceutical sciences and is the co-founder/former Chief Scientific Officer of Aldevron in Fargo, North Dakota. He proposed questions, concerns, and ideas from an experienced viewpoint about our biomanufacturing processes. With a background in large scale plasmid, mRNA, and protein production, he provided insight that we hope to implement into the future biomanufacturing of our chromoprotein.
One thing we kept in mind throughout the duration of the project was the accessibility of our biological dye. This dye is aimed at benefiting developing countries as a majority of textile production is focused in these countries. John proposed a variety of logistical suggestions we should consider if our dye was implemented at a large scale in the textile industry.
He raised the question of how we would combat job losses in the textile industry if our dye was implemented in a large-scale manner. One of our standards we kept in mind was protecting the people that work in textiles to support their families. We would aim to make our biomanufacturing accessible to people that may have little to no knowledge of synthetic biology. Our work on this year’s project was primarily focused on creating a functional protein dye. If this project were to be continued next year, streamlining our process would be one of our priorities. Even though this is far in the future, we have started brainstorming how we can simplify our process and make it accessible globally.
Azo dyes found in textile wastewater can be detrimental to surrounding waterways and the communities that utilize them. Azo dyes polluting aquatic environments have highly stable chemical structures, therefore making them difficult to degrade once present in water (1). While in the beginning stages of our project, we aimed to find a product that would be safer in wastewater after the dyeing process. This research shifted our focus to a chromoprotein dye that could reduce the presence of azo dyes in wastewater. After the dyeing of textiles with our alternative dye, it would then theoretically denature naturally, leaving little to no residue. However, our team did not conduct research on what or if residues are present after dyeing textiles. Reducing the impact of azo dyes in aquatic environments has been a primary focus of our project, as we want our dye to benefit those directly affected by textile dye contamination.
For our dye to produce the most vivid color, we opted for an inducible promoter that would allow for maximized protein production. The arabinose inducible promoter we implemented in our construct resulted in a vibrant, more concentrated dye. Constructs 50 and 60 in the results page demonstrate the visible comparison of two samples with and without our inducible promoter. Vibrant colors are in high demand and are found throughout industry. We wanted to create an accurate color substitution for the currently used azodyes. Both brightness and sustainability can be achieved without one being prioritized over another.
Our protein based dye will not only be safer for the people wearing these garments but it will also be safer for the people making them. Textile workers involved in the dying process have the highest risk of developing health problems due to their direct and prolonged exposure to fabric dyes. Chemical compounds found in azo dyes are reported to cause bladder cancer in workers (6). There are similar reports of cancer in the lungs, pancreas, liver, and stomach. Which are typically associated with the inhalation and/or dermal absorption of azo dyes containing benzidine, classified as a category 1 carcinogen (3). Our chromoprotein has been established as non-toxic and safe for living tissue without causing any damage to cells. Currently, mScarlet is predominantly successful as a biomarker for functional cellular imaging in neurons. Using mScarlet to synthesize a fluorescent pigment for fabric dye will improve the occupational safety of industrial facilities.