AbstractSome aspects of the regulation of α‐amylase synthesis inBacillus licheniformisCCM 2205 were investigated. The effect of actinomycin D and chloramphenicol was studied at the level of RNA transcription and translation, α‐amylase synthesis inBacillus licheniformisCCM 2205 was practically not altered during the first 20 min after the addition of actinomycin D, although RNA synthesis was almost completely blocked. In contrast to RNA polymerase inhibitor, chloramphenicol stopped immediately the synthesis of α‐amylase. By using the least squares method the mean half‐life of α‐amylase mRNA was calculated to range from 7.5 to 8.4 min. The mean half‐life of cell protein mRNA was determined to range from 2.6 to 3.8 min. Having in mind the immediate effect of chloramphenicol on the α‐amylase synthesis, it can be concluded that de novo protein synthesis is required in the case of actinomycin D resistant