Eco-friendly Bio-manufacturing of Flavonoid Dyes in Escherichia coli via Computer-mediated Optogenetic Regulation
Natural dyes are increasingly considered as an eco-friendly solution to the serious water pollution generated by the textile and dye industries. Traditional production of natural dyes from plants heavily exhausts land and labour. While bio-manufacturing is an attractive alternative, it remains costly and chemically-intensive. We aim to develop a new bio-manufacturing method of producing flavonoids in E. coli for use as natural dyes. To eliminate the use of expensive chemical inducers to switch from growth to production phase and allow dynamic gene regulation, we designed an optogenetic circuit using a blue light repressible promoter for flavonoid biosynthesis. As it is critical to monitor cellular metabolic burden for efficient production, we introduced a stress-sensing fluorescence reporter. To optimize operations, a computer-aided system was developed to regulate gene expression using light according to the feedback from the stress sensor. To demonstrate this approach, we produced Luteolin, a natural yellow dye.