Application of cyclodextrin to microbial transformation of vitamin D3 to 25-hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3

Abstract Amycolata autotrophica converts vitamin D 3 (VD 3 ) to 1α,25-dihydroxyvitamin D 3 (1α,25(OH) 2 VD 3 ) via 25-hydroxyvitamin D 3 (25(OH)VD 3 ) by hydroxylation of VD 3 at C-25 and C-1. In this microbial hydroxylation, it was found that cyclodextrin (CD) had the ability to enhance the hydroxylation of VD 3 . Addition of partially-methylated-β-cyclodextrin (PMCD) increased the productivity of 25(OH)VD 3 about seven-fold compared to that without CD. Combined use of PMCD and γ-CD increased the production of 1α,25(OH) 2 VD 3 in a tank fermentor about sixteen-fold compared to that without CD.