Obtaining metabolic mutants involving random mutations and specific selection not having recombinant DNA and a nucleic acid cassette encoding a bidirectional marker, and inducible enhancer and a basic transcription unit

摘要

A nucleic acid cassette comprising a nucleic acid sequence encoding a bidirectional marker is claimed. The nucleic acid cassette further comprises a basic transcriptional unit operatively linked to the nucleic acid sequence encoding the bidirectional marker. The nucleic acid cassette further comprises an inducible enhancer or activator sequence linked to the basic transcription unit in such a manner that upon induction of the enhancer or activator sequence the bidirectional marker encoding nucleic acid sequence is expressed. The inducible enhancer or activator sequence is derived from a gene associated with activity of part of metabolism, said inducible enhancer or activator sequence being derived from a gene associated with metabolism.