Biosynthesis and preparation of phycoerythrobilin in recombinant Escherichia coli

Phycoerythrobilin (PEB) is a special pigment in red algae and cyanobacteria that plays an important role in capturing light energy. As a natural non-toxic pigment with antioxidant properties, PEB is widely used in food and cosmetics industries. At present, the presence of other pigments in red algae and cyanobacteria, such as chlorophyll and phycocyanobilin, makes the preparation of PEB complicated and costly. In this study, the PEB synthesizing enzyme genes of hox1 from Synechocystis sp. PCC6803 and pebS from Nostoc sp. PCC 7120 were co-expressed in Escherichia coli to produce recombinant PEB. In addition, single-factor and response surface methods were used to enhance the yield of recombinant PEB. Under the conditions of lactose concentration at 4 mmol L−1, induction temperature at 27 °C, OD600 nm of 0.9, and induction time at 14 h, the concentration of PEB reached 20.37 mg L−1. In addition, a high-purity (purity > 70%) PEB was obtained through chloroform extraction, and the purified product was verified in UV spectrometry, high-performance liquid chromatography, and mass spectrometry.