Biotransformation to Produce Boldenone by Pichia pastoris GS115 Engineered Recombinant Strains

Yeast as a promising heterologous host for steroid bioproduction

“…Boldenone (BD), the precursor to a number of steroid medicines, is normally synthesized from AD through ∆ 1 dehydrogenation and 17-keto reduction (Fig. 2, Table 1) [49]. A number of yeast strains have been found to be able to catalyze steroid 17β-reduction natively, including Pichia pastoris GS115 [49].…”

“…2, Table 1) [49]. A number of yeast strains have been found to be able to catalyze steroid 17β-reduction natively, including Pichia pastoris GS115 [49]. One recent example of yeast-based bioproduction of BD was achieved through overexpressing the 3-ketosteroid-Δ 1 -dehydrogenase KsdD2 from Rhodococcus rhodochrous in GS115 [49].…”

“…A number of yeast strains have been found to be able to catalyze steroid 17β-reduction natively, including Pichia pastoris GS115 [49]. One recent example of yeast-based bioproduction of BD was achieved through overexpressing the 3-ketosteroid-Δ 1 -dehydrogenase KsdD2 from Rhodococcus rhodochrous in GS115 [49]. Both ∆ 1 dehydrogenated product androst-1,4-ene-3,17-dione (ADD) from AD and 17-keto reduced product BD from ADD were detected from the engineered yeast strain, indicating the 2-step formation of BD from AD in GS115 [49].…”

“…One recent example of yeast-based bioproduction of BD was achieved through overexpressing the 3-ketosteroid-Δ 1 -dehydrogenase KsdD2 from Rhodococcus rhodochrous in GS115 [49]. Both ∆ 1 dehydrogenated product androst-1,4-ene-3,17-dione (ADD) from AD and 17-keto reduced product BD from ADD were detected from the engineered yeast strain, indicating the 2-step formation of BD from AD in GS115 [49]. However, the conversion efficiency of AD into BD is low, at around 30% due to the insolubility of steroid in aqueous solution (AD was fed at 2 g/L).…”

“…However, the conversion efficiency of AD into BD is low, at around 30% due to the insolubility of steroid in aqueous solution (AD was fed at 2 g/L). Therefore, the cosolvent 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was supplemented to improve the solubility of steroids in the medium and enhanced the conversion of AD into BD to 56.76% (with molar ratio 1: 1 of HP-β-CD to AD) [ 49 ]. The conversion was further improved with the bacterial and yeast co-culture strategy in the follow-up investigations [ 50 , 51 ].…”