Team:Berkeley/Project

The world consumes over 40 million kilograms of indigo annually, primarily for dyeing denim. Indigo is currently derived from petroleum using a high energy process, and commercial dyeing involves the use of reducing agents to solubilize the dye. The development of biosynthetic and bioprocessing methodologies for indigo dyeing could have environmental and economic advantages. By combining the biosynthesis of indigo and the use of the natural indigo precursor indican, we propose a more sustainable dyeing method as an alternative to chemically-reduced indigo in the large scale production of indigo textiles. We achieved in vivo indigo production in high titers, and efficient cleavage of indican using a non-native glucosidase. Inspired by natural systems, we isolated and characterized several plant and bacterial glucosyl transferases hypothesized to produce indican. Lastly, we compare the cost and environmental impact of our alternative with the present chemical process.

The world produces over 40,000 tons of indigo per year to be able to dye 3 billion pairs of jeans. Unfortunately, the indigo production and dyeing industries utilize a variety of harmful chemicals (link to the image of harmful chemicals). Given previous iGEM interest in indigo and the need for a greener alternative to denim dyeing, we started our project – Blue Genes.

This summer we have taken inspiration from plant metabolic pathways to devise a biosynthetic approach to dyeing jeans with indigo. In the process, we have characterized main components of the metabolic pathway. In addition we have analyzed the scale up involved in taking our project from the bench to industry highlighting steps that need improvement as well as potential cost-energy savings.