Efficient marker free CRISPR/Cas9 genome editing for functional analysis of gene families in filamentous fungi

Microbial Biotechnolog

Mutations in AraR leading to constitutive of arabinolytic genes in Aspergillus niger under depressing conditions

Plant science

Loss of function of the carbon catabolite repressor CreA leads to low but inducer-independent expression from the feruloyl esterase B promoter in Aspergillus niger

Microbial Biotechnolog

The transcriptional activator GaaR of Aspergillus niger is required for release and utilization of D-galacturonic acid from pectin

Microbial Biotechnolog

Progress and Research Needs of Plant Biomass Degradation by Basidiomycete Fungi

Peer reviewe

Discovery and exploitation of the transcriptional regulatory system of pectinases in Aspergillus niger

Pectin is a plant cell wall polysaccharide made of mainly D-galacturonic acid (GA) subunits. The potency of the filamentous fungus Aspergillus niger to naturally secrete high amounts of pectinases to degrade pectin has been utilized for the industrial production of pectinases. Industrially produced pectinases by A. niger are subsequently used mainly in the food industry, and for the hydrolysis of plant biomass to produce renewable energy. In this thesis, the key players in the transcriptional regulatory system of pectinases in A. niger, such as the transcriptional activator GaaR, the repressor GaaX and the physiological inducer 2-keto-3-deoxy-L-galactonate, are discovered. Several approaches to exploit this system for increased or constitutive expression of the genes encoding pectinases are also presented, such as overexpression and constitutive activation of gaaR, accumulation of 2-keto-3-deoxy-L-galactonate, and deletion of gaaX or creA, the main transcriptional repressor involved in CCR.</p

W361R mutation in GaaR, the regulator of D-galacturonic acid-responsive genes, leads to constitutive production of pectinases in Aspergillus niger

Microbial Biotechnolog

An Evolutionarily Conserved Transcriptional Activator-Repressor Module Controls Expression of Genes for D-Galacturonic Acid Utilization in Aspergillus niger

Microbial Biotechnolog

Inducer-independent production of pectinases in Aspergillus niger by overexpression of the D-galacturonic acid-responsive transcription factor gaaR

Microbial Biotechnolog

Functional analysis of three putative galactofuranosyltransferases with redundant functions in galactofuranosylation in Aspergillus niger

Galactofuranose (Galf)-containing glycostructures are important to secure the integrity of the fungal cell wall. Golgi-localized Galf-transferases (Gfs) have been identified in Aspergillus nidulans and Aspergillus fumigatus. BLASTp searches identified three putative Galf-transferases in Aspergillus niger. Phylogenetic analysis showed that they group in three distinct groups. Characterization of the three Galf-transferases in A. niger by constructing single, double, and triple mutants revealed that gfsA is most important for Galf biosynthesis. The growth phenotypes of the ΔgfsA mutant are less severe than that of the ΔgfsAC mutant, indicating that GfsA and GfsC have redundant functions. Deletion of gfsB did not result in any growth defect and combining ΔgfsB with other deletion mutants did not exacerbate the growth phenotype. RT-qPCR experiments showed that induction of the agsA gene was higher in the ΔgfsAC and ΔgfsABC compared to the single mutants, indicating a severe cell wall stress response after multiple gfs gene deletions.Microbial Biotechnolog