The industrial dyeing process is ecologically unfriendly - indigo is made from an oil derivative (benzene) using harsh chemicals and extremely high temperatures. Furthermore, for indigo to actually adhere to fabric, a reducing agent is necessary to solubilize the dye, and this process releases acidified wastewaters into local environments.
Research has shown that the leaves of indigo-producing plants contain two enzymes, a glucosyltransferase (GT) and a glucosidase (GLU), which together control indigo solubility by interconverting indigo with a soluble form called indican. We propose a biological dyeing method that harnesses this pathway in a bacterial chassis.
For the first time, indican has been produced using a recombinant GT as a result of our work. We prove indican irreversibly dyes fabric with the use of a GLU. Lastly, we have examined ways to reduce our new system’s costs by optimizing indoxyl (an indican precursor) production and taking into account other innovative design choices.
Our work has created an entirely new way to dye denim with purely biological inputs which, with continued optimization, could compete economically with current industrial methods.
Read on to learn more about our nature-inspired system!
The UC Berkeley iGEM team would like to thank Autodesk, Agilent, Synthetic Biology Institute, Qualcomm, Dean A. Richard Newton Memorial Chair for their financial support, IDT for discounted oligos and Quintara Bio for discounted sequencing service.