Bioproduction of Biliverdin from Heme Using Recombinant Pichia pastoris Cells
Biliverdin, a bile pigment transformed from heme by heme oxygenase (HO), serves multiple functions in the human body, including antioxidant, anti-inflammatory, and immune response inhibitory activities. In this research, the production of biliverdin by biotransformation of exogenous heme was investigated using recombinant HO-expressing yeast cells. The heme oxygenase-1 gene (HO1) encoding an inducible plastidic isozyme from Arabidopsis thaliana, was recombined into Pichia pastoris GS115 cells with the plastid transport peptide sequence removed. Then the whole cells of GS115-HO1 were employed as catalysts to convert heme chloride (hemin) into biliverdin. It was shown that the yield of biliverdin was 132 mg/L when hemin (0.8 g/L) was added to the culture of GS115-HO1 and incubated for 4 h at 30 °C. The findings of this study have laid a good foundation for future applications of this method for the economical bioproduction of biliverdin.