A mutant, TS-N-121 was obtained by mutation and plate screening from a parent strain Mycobacterium fortuitum MF2 , which could transform sterol into androstanedione as the main product.

从雄甾二酮的转化产生菌偶发分枝杆菌MF2出发,经紫外诱变结合平板筛选,获得一株主要转化生产睾酮的突变株TS-N-121。