Project description:Genomic and proteomic characterization of the Aspergillus niger isolate, JSC-093350089, collected from U.S. segment surfaces of the International Space Station (ISS) is reported, along with a comparison to the experimentally established strain ATCC 1015. Whole-genome sequencing of JSC-093350089 revealed enhanced genetic variance when compared to publicly available sequences of A. niger strains. Analysis of the isolate’s proteome revealed significant differences in the molecular phenotype of JSC-093350089, including increased abundance of proteins involved in the A. niger starvation response, oxidative stress resistance, cell wall integrity and modulation, and nutrient acquisition. Together, these data reveal the existence of a distinct strain of A. niger onboard the ISS and provide insight into the molecular phenotype that is selected for by melanized fungal species inhabiting spacecraft environments.
Project description:The genome of the filamentous fungus Aspergillus niger is rich in genes encoding pectinases, a broad class of enzymes that have been extensively studied due to their use in industrial applications. The sequencing of the A. niger genome provided more knowledge concerning the individual pectinolytic genes, but relatively little is still known about the regulatory genes involved in pectin degradation. Understanding regulation of the pectinolytic genes provides a tool to optimize the production of pectinases in this industrially important fungus. This study describes the identification and characterization of one of the activators of pectinase-encoding genes, RhaR. Inactivation of the gene encoding this regulator resulted in down-regulation of genes involved in the release and catabolism of L-rhamnose from the pectinolytic substructure rhamnogalacturonan I.
Project description:Gene expression was studied at the periphery, an intermediate zone, and the centre of wild-type and ∆flbA colonies using Affymetrix A. niger whole genome microarrays. We used Affymetrix GeneChip A. niger Geome Arrays and identifed up- and down-regulated genes that may account for the differences between wild-type and ΔflbA colonies.
