Sterol-side chain cleavage by fusants ofAlkaligenes fœcalis andArthrobacter oxydans

Protoplasts of a strain ofA. fœcalis incapable of utilizing β-sitosterol as carbon source for growth were fused with protoplasts ofA. oxydans — a strain capable of complete degradation of β-sitosterol. Five fusants showing morphology and pattern of transformation of C-19 steroids identical toA. Fœcalis were selected. Analysis of the fermentation broth containing β-sitosterol showed that the fusants were capable of utilizing β-sitosterol for growth but their pattern of metabolite formation from β-sitosterol was different from that ofA. oxydans. The study revealed that the protoplast fusion technique could be used for intergeneric transfer of genetic determinants linked to partial cleavage of β-sitosterol side chain toA. fœcalis fromA. oxydans.