The side chains of sterols are degraded by fermentation with microorganisms capable of doing so in an improved manner by employing in such fermentations sterol derivatives of the formula ##STR1## wherein n is 1 or 2; R.sub.1 is H or lower alkyl, R.sub.2 is alkyl, whose chain optionally is interrupted by an oxygen atom, or when n is 2, also a hydrogen atom; and R.sub.3 is a sterol side chain.
类
固醇的侧链通过使用能够进行这种改进的微
生物发酵降解,通过在这种发酵中使用如下公式的类
固醇衍
生物来实现:##STR1## 其中n为1或2; R.sub.1为H或较低的烷基,R.sub.2为烷基,其链可选择性地被氧原子中断,或当n为2时,也可为氢原子; R.sub.3为类
固醇侧链。