Engineering artificial biosynthetic pathway enables simultaneous production and in-situ bio-dyeing of indigoids for textiles

The textile dyeing industry has shaped modern aesthetics through vibrant coloration technologies. Indigoid dyes embody this potential but are hindered by the hazardous chemo-synthesis and water-intensive chemo-dyeing processes. While biosynthesis and bio-dyeing efforts offer alternatives, disjointed synthesis-dyeing steps lead to unsustainable water and energy demands, and complex biosynthetic pathways cause low atom economy and inefficiency. Here, we report a one-pot one-step approach that unifies biosynthesis and bio-dyeing of indigoids to drastically reduce water usage in the dyeing process. By combining alcohol dehydrogenase with flavin-containing monooxygenase, we construct an artificial redox-neutral cascade biosynthetic pathway to produce bluish-violet indigoid dyes, which significantly enhances atom economy and achieves high production efficiency. Various natural and synthetic fabrics are dyed in-situ with the biosynthetic indigoids utilizing recombinant E. coli whole cells. Crucially, this system dyes synthetic nylon fibers with the historic purple hue.