Biotransformation of isoflavones daidzein and genistein by recombinant Pichia pastoris expressing membrane-anchoring and reductase fusion chimeric CYP105D7

Using N-terminal fusion with transmembrane domain of CYP57B3 from Aspergillus oryzae and C-terminal fusion with a P450 reductase from Saccharomyces cerevisiae, CYP105D7 from Streptomyces avermitilis MA4680 was expressed as a reductase fusion and membrane-anchoring form in Pichia pastoris. Recombinant P. pastoris expressing the chimera catalyzed both biotransformation of daidzein and genistein into 6-hydroxydaidzein and 3ʹ-hydroxygenistein, respectively. The recombinant P. pastoris produced 6-hydroxydaidzein and 3ʹ-hydroxygenistein with maximal yields of 7.5 and 15 mg/l, where the production of 3ʹ-hydroxygenistein was higher than those previously reported. The present study demonstrated that substrate spectrum and product yields of biotransformation from soy isoflavones into ortho-hydroxyisoflavones by bacterial CYP105D7 could be improved through membrane-anchoring and reductase fusion expression in P. pastoris.65