The Aspergillus nidulans velvet (veA) gene encodes a global regulator of gene expression controlling sexual development as well as secondary metabolism. We have identified the veA homologue AcveA from Acremonium chrysogenum, the major producer of the -lactam antibiotic cephalosporin C. Two different disruption strains as well as the corresponding complements were generated as a prelude to detailed functional analysis. Northern hybridization and quantitative real-time PCR clearly indicate that the nucleus-localized AcVEA polypeptide controls the transcriptional expression of six cephalosporin C biosynthesis genes. The most drastic reduction in expression is seen for cefEF, encoding the deacetoxycephalosporine/deacetylcephalosporine synthetase. After 120 h of growth, the cefEF transcript level is below 15% in both disruption strains compared to the wild type. These transcriptional expression data are consistent with results from a comparative and time-dependent high-performance liquid chromatography analysis of cephalosporin C production. Compared to the recipient, both disruption strains have a cephalosporin C titer that is reduced by 80%. In addition to its role in cephalosporin C biosynthesis, AcveA is involved in the developmentally dependent hyphal fragmentation. In both disruption strains, hyphal fragmentation is already observed after 48 h of growth, whereas in the recipient strain, arthrospores are not even detected before 96 h of growth. Finally, the two mutant strains show hyperbranching of hyphal tips on osmotically nonstabilized media. Our findings will be significant for biotechnical processes that require a defined stage of cellular differentiation for optimal production of secondary metabolites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.