Recent Advances in Microbial Synthesis of Indigo

This is the authors' abstract. We don't add key points for this paper.

Indigo is one of the organic pigments which is widely used in printing,dyeing and pharmaceutical industries.Microbial synthesis of indigo has recently attracted extensive attention worldwide.The research processes and development trends are reviewed in the present paper.Biosynthesis of indigo could be divided into three periods: Biosynthesis by wild microbes,whole-cell catalysis by engineering bacteria and biotransformation regulated by metabolic engineering.Most aromatic-degrading microbes and their relevant enzymes possess the ability to convert indole to indigo.New technologies such as directed evolution,metagenome and two phase reaction system could facilitate in-depth investigations of the enzyme resources,and they will play a crucial role in the indigo biosynthesis research.Meanwhile,hydroxyl-indoles and indigo derivatives produced in the process are promising pharmaceutical and chemical precursors with great research interests.However,the transformation interactions between intermediates and by-products are still unclear.Besides,low indigo yield and efficiency with high cost have hampered practical production.Therefore,it is essential to combine the molecular biology and metabolic engineering technologies to investigate the mechanisms and industrial application of indigo biosynthesis in the future.