“…230 Recently, Zhu and coworkers knocked out of a β-hydroxyacyl-CoA dehydrogenase gene and introduced a sterol aldolase gene in the genetically modified strains of Mycobacterium fortuitum N13, resulting in the strain N13Δhsd4AΩthl. 231 It transformed phytosterols into 3-((1R,3aS,4S,7aR)-1-((S)-1-hydroxypropan-2-yl)-7a-methyl-5-oxooctahydro-1H-inden-4-yl) propanoic acid (HIP-IPA, 197) in 62% isolated yield, which is a key intermediate for the synthesis of dydrogesterone (Fig. 32).…”