Fig. 1

Biosynthetic pathway of anthocyanins (labeled in pink) in plants and the introduced pathway for cyanidin 3-O-glucoside production from catechin in C. glutamicum. The introduced pathway consisting of ANS and 3GT is highlighted in red, and the biosynthetic pathway of UDP-glucose in C. glutamicum is marked in green. Abbreviations of the enzymes in the pathway: PAL phenyl ammonia lyase, TAL tyrosine ammonia lyase, C4H cinnamate 4-hydroxylase, 4CL 4-coumaroyl-CoA ligase, CHS chalcone synthase, CHI chalcone isomerase, F3′H flavonoid 3′-hydroxylase, F3′5′H flavonoid 3′,5′-hydroxylase, F3H flavanone 3-hydroxylase, DFR dihydroflavonol 4-reductase, LAR leucocyanidin reductase, ANS anthocyanidin synthase, 3GT flavonoid 3-O-glucosyltransferase, GLK glucokinase, PGM phosphoglucomutase, GalU1 UTP-glucose-1-phosphate uridylyltransferase