GREENDIGO · Biosolutions for Denim Dyeing within the Planetary Boundaries

The global denim industry, producing over 3 billion pairs of jeans annually, is one of the most chemically intensive sectors in textiles. Conventional indigo dyeing relies on fossil-derived synthetic indigo and toxic reducing agents such as sodium hydrosulfite, resulting in widespread water pollution, hazardous working conditions, and high energy and chemical input. GREENDIGO aims to revolutionise this process by developing the first fully enzymatic, biobased dyeing method for denim that is scalable, safe, and sustainable. The project will replace conventional indigo with a water-soluble precursor, which can be adsorbed onto cotton fibres under mild aqueous conditions. A specific enzyme will catalyse its in-situ conversion to indigo directly on the fabric, eliminating the need for harmful reductants and enabling a cleaner, circular textile value chain. GREENDIGO will combine cutting-edge enzyme engineering, synthetic biology, and textile chemistry with advanced sustainability assessment to ensure the process is economically viable, environmentally safe, and aligned with planetary boundaries. The project applies the EC’s Safe and Sustainable by Design (SSbD) framework from the outset and integrates life cycle analysis, ecotoxicity testing, and absolute sustainability modelling. Outcomes will be benchmarked against current practices, with particular attention to emissions, resource use, and scalability. If successful, GREENDIGO will lay the scientific and technological foundation for a new class of biosourced textile dyes, enabling the reindustrialisation of denim dyeing under strict environmental standards. The project supports key EU priorities, including the Green Deal, the EU Strategy for Sustainable and Circular Textiles, and zero pollution targets.