Fig. 5
From: Complete microbial synthesis of crocetin and crocins from glycerol in Escherichia coli
Construction of crocin-1 and 2 pathways and crocin-1 and 2 production in batch bioreactor fermentations. (A) HPLC and UV/Vis analysis of in vitro activity of three first-step UGT candidates (GjUGT1, GT1-316, and NtUGT) for determining the glycosylation activity on crocetin. Peak 1 corresponds to crocin-2; peak 2, crocin-1; peak 3, crocetin. (B) UV/VIS spectrum corresponds to each HPLC chromatogram peak (A). (C) HPLC analysis of UDP-glucose-dependent activity of NtUGT in the in vitro reaction. The assignment of peaks is the same as that of (A). (D) HPLC analysis of culture medium (upper) and Z1pCA7942(P) cell extract pN. The assignment of peaks in the HPCL chromatogram is the same as that of (A). (E) LC/MS analysis of crocin-2 [peak 1 in (D)] and crocin-1[peak 2 in (D)]. (F) Cell growth and glycerol consumption in batch bioreactor fermentations of the Z1pCA7942(P)pN strain at 20℃ (upper). Quantifying the time-course production of crocin-1, crocin-2, and crocetin in bioreactor batch fermentations (lower). Bioreactor fermentations were performed in biological triplicate, and error bars represent mean ± SD