Project description:In submerged cultivation of filamentous microbes, including actinomycetes, complex morphology is one of the critical process features for secondary metabolites production. Ansamitocin P-3 (AP-3), an antitumor agent, is a secondary metabolite produced by Actinosynnema pretiosum ATCC 31280. An excessive mycelial fragmentation of A. pretiosum ATCC 31280 was observed during the early stage of fermentation. In order to identify genes involved in the early mycelial fragmentation, the total RNAs of mycelia collected at 15, 18, and 24 h were extracted and subjected to transcriptome sequencing using RNA-seq technology.Through comparative transcriptomic analysis, a subtilisin-like serine peptidase encoded gene APASM_4178 was identified to be responsible for the mycelial fragmentation. Mutant WYT-5 with the APASM_4178 deletion showed increased biomass and improved AP-3 yield by 43.65%.