A new biotechnological process for the production of testosterone (TS) has been developed to turn the model strain Mycobacterium smegmatis suitable for TS production to compete with the current chemical synthesis procedures. We have cloned and overexpressed two genes encoding microbial 17β-hydroxysteroid: NADP 17-oxidoreductase, from the bacterium Comamonas testosteroni and from the fungus Coch...