Year/Course: 2016-2017, Easter 2017

Researchers: Dr James Ajioka & Dr. Orr Yarkoni, Colorifix
Mentors: Natsai Audrey Chieza & Daisy Ginsberg

Dyeing is a surprisingly dirty business. Whether they are chemically synthesized or naturally sourced, dyes have a profound impact on the environment. Dye production involves either refining of petrochemicals for chemical synthesis precursors or the extraction of natural pigments using solvents; both are processes that require harmful chemicals and their use carries an environmental impact. The act of dyeing itself also carries a significant environmental impact. Several additives, many of them toxic (such as phenols, formaldehydes and heavy metals) are introduced to the dyeing mix to enhance the deposition and fixation of dyes onto textiles. The textile industry is the third largest consumer of water, using upwards of 9 trillion litres of water a year, 6 trillion of which come from the dyeing and finishing steps. This is because dyeing uses a very high ratio of water to fabric, with 50/1 being common, 30/1 being the norm and 10/1 being considered a substantial achievement. The dye bath is then heated to temperatures exceeding 100C for several hours for the dyeing step to take place. The World Bank estimates that roughly 20% of all industrial water pollution comes from the dye industry, making it one of the most polluting industries on the planet. The industry standard for waste dye in effluent is 3%, with many dyers failing to meet this standard and paying substantial fines.

Colorifix has developed a whole new way of dyeing fabrics. The scientists who started the company engineered microorganisms so that they produce, deposit and fix dyes directly onto fabrics, using a water/fabric ratio of 3/1 and managing a 1% dye waste in effluent, whilst avoiding the use of any toxic chemicals or solvents. This is possible because the microorganism acts as a microreactor, bringing dyes and ions into close proximity with the fabric. Once the microorganisms are killed, they release their content directly onto the fibres, resulting in efficient, colourfast dyeing.

Some of the areas most affected by the dyeing industries are in emerging economies such as India. In 2016, several dye houses were shut down by the Namami Gange Programme as they were found to produce unacceptably high levels of pollution that was contaminating river water.

The Development i-Team will explore the requirements for commercialisation of the Colorifix technology in India. This is not straightforward, as there are regulatory, governmental, safety, cultural, economic and environmental aspects that must be investigated to establish the feasibility of using a synthetic biology approach in a country with very strict GMO regulations.

Dr. James Ajioka is a Senior Lecturer in the Department of Pathology, and a member of the Synthetic Biology SRI Committee.