procedure for the manufacture of a strain, particularly a gaerstamme, which is transformed with a ekspressionsvektor and which can be grown on a complete medium without selektionstryk,and thus gained strain

摘要

Process for the preparation of a strain transformed by a cloning or expression vector of a gene coding for a predetermined protein which may be cultivated on a complete medium without selection pressure, characterized in that: a) a metabolite of which the absence is lethal for the strain and which is synthetized by at least two metabolic pathways is identified, b) a first pathway of said metabolic pathways is blocked by alteration of at least one of the genes implied in said pathway, c) the strain is transformed by the vector which additionally comprises the functional allele of the altered gene, and d) the other metabolic pathways are blocked.