HPLC elution profiles of cholesterol bioconversions by R. rhodochrous DSM43269 wild type (a), kshA null mutant strain RG32 (b), and recombinant RG32 strains transformed with either kshA1 (c), kshA2 (d), kshA3 (e), kshA4 (f), or mutant strain RG31 harboring kshA5 (g).