title: Deletion of flbA results in increased secretome complexity and reduced secretion heterogeneity in colonies of Aspergillus niger.
abstract: Aspergillus niger is a cell factory for the production of enzymes. This fungus secretes proteins in the central part and at the periphery of the colony. The sporulating zone of the colony overlapped with the nonsecreting subperipheral zone, indicating that sporulation inhibits protein secretion. Indeed, strain ΔflbA that is affected early in the sporulation program secreted proteins throughout the colony. In contrast, the ΔbrlA strain that initiates but not completes sporulation did not show altered spatial secretion. The secretome of 5 concentric zones of xylose-grown ΔflbA colonies was assessed by quantitative proteomics. In total 138 proteins with a signal sequence for secretion were identified in the medium of ΔflbA colonies. Of these, 18 proteins had never been reported to be part of the secretome of A. niger, while 101 proteins had previously not been identified in the culture medium of xylose-grown wild type colonies. Taken together, inactivation of flbA results in spatial changes in secretion and in a more complex secretome. The latter may be explained by the fact that strain ΔflbA has a thinner cell wall compared to the wild type, enabling efficient release of proteins. These results are of interest to improve A. niger as a cell factory.
authors: Microbiology and Kluyver Centre for Genomics of Industrial Fermentation, Utrecht University , Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors: Pauline
authors: P
authors: Krijgsheld
authors: Benjamin M
authors: BM
authors: Nitsche
authors: Harm
authors: H
authors: Post
authors: Ana M
authors: AM
authors: Levin
authors: Wally H
authors: WH
authors: Müller
authors: Albert J R
authors: AJ
authors: Heck
authors: Arthur F J
authors: AF
authors: Ram
authors: A F Maarten
authors: AF
authors: Altelaar
authors: Han A B
authors: HA
authors: Wösten
mesh_terms: D001234:Aspergillus niger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D025301:Hyphae / Q000187:drug effects; D040901:Proteomics / Q000379:methods; D012100:Reproduction, Asexual; D013172:Spores, Fungal / Q000254:growth & development; D014994:Xylose / Q000378:metabolism
chemical_list: D003470:Culture Media; D005656:Fungal Proteins; D003513:Cycloheximide; D014994:Xylose