METHOD FOR ISOLATING AND SELECTING GENES CODING FOR ENZYMES, AND SUITABLE CULTURE MEDIUM

摘要

The invention concerns a method for selecting and/or isolating DNA sequences coding for enzymes involved in the biological conversion of an appropriate substrate consisting of methionine and its derivatives, such as HMTBS, said method comprising the following steps: 1) cloning DNA sequences in a carrier enabling their expression in an appropriate host micro-organism; 2) transforming a suitable auxotroph micro-organisms for methionine by introducing carriers previously obtained in said suitable micro-organism; 3) growing the transformed micro-organisms previously obtained in a suitable culture medium comprising a sufficient amount of appropriate substrate; and 4) selecting the transformed micro-organisms capable of growing in the appropriate culture medium; and 5) isolating and as the case may be identifying the DNA sequences involved in the biological conversion of the appropriate substrate.