Topic overview

Start with the big picture

Microorganisms can carry out targeted steroid modifications that may be difficult to achieve through chemical methods alone. Examples include hydroxylation at positions such as C11, C16, and C9; Δ¹-dehydrogenation; side-chain cleavage; and reductive or oxidative changes. The snapshot links particular reactions to organisms—for example, Rhizopus species to 11β-hydroxylation and Mycobacterium or Rhodococcus to conversion of phytosterols into steroid intermediates. It also describes aromatization and less common transformations that broaden the range of possible products. The deeper lesson organizes these reactions by type and considers process engineering, industrial and regulatory considerations, and the advantages of microbial methods, including enzyme specificity and operation under relatively mild conditions.