Three gene clusters controlling the biosynthesis of the antibiotics actinorhodin(ACT),undecylprodigiosin(RED)and calcium-dependent antibiotic(CDA)were sequentially knockouted by gene replacements from the chromosome of Streptomyces lividans TK24to derive SBT5.In SBT5,the global regulatory genes afsRScla fromStreptomyces clavuligerus was integrated in the place of the cda gene cluster.The act gene cluster fromStreptomyces coelicolor was introduced into SBT5to test its capability of expressing secondary gene ...