AcAxl2 and AcMst1 regulate arthrospore development and stress resistance in the cephalosporin C producer Acremonium chrysogenum.
Curr Genet
; 64(3): 713-727, 2018 Jun.
Article
em En
| MEDLINE
| ID: mdl-29209784
ABSTRACT
The filamentous fungus Acremonium chrysogenum is the primordial producer of the ß-lactam antibiotic cephalosporin C. This antibiotic is of major biotechnological and medical relevance because of its antibacterial activity against Gram-positive and Gram-negative bacteria. Antibiotic production during the lag phase of fermentation is often accompanied by a typical morphological feature of A. chrysogenum, the fragmentation of the mycelium into arthrospores. Here, we sought to identify factors that regulate the hyphal septation process and present the first comparative functional characterization of the type I integral plasma membrane protein Axl2 (axial budding pattern protein 2), a central component of the bud site selection system (BSSS) and Mst1 (mammalian Sterile20-like kinase), a septation initiation network (SIN)-associated germinal center kinase (GCK). Although an Acaxl2 deletion strain showed accelerated arthrospore formation after 96 h in liquid culture, deletion of Acmst1 led to a 24 h delay in arthrospore development. The overexpression of Acaxl2 resulted in an arthrospore formation similar to the A3/2 strain. In contrast to this, A3/2Acmst1 OE strain displayed an enhanced arthrospore titer. Large-scale stress tests revealed an involvement of AcAxl2 in controlling osmotic, endoplasmic reticulum, and cell wall stress response. In a similar approach, we found that AcMst1 plays an essential role in regulating growth under osmotic, cell wall, and oxidative stress conditions. Microscopic analyses and plating assays on media containing Calcofluor White and NaCl showed that arthrospore development is a stress-dependent process. Our results suggest the potential for identifying candidate genes for strain improvement programs to optimize industrial fermentation processes.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Esporos Fúngicos
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Acremonium
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Proteínas Fúngicas
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Cefalosporinas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Curr Genet
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Alemanha