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:Using transcriptomics, the strain-specific metabolism was mapped for two whole-genome sequenced strains of Aspergillus niger Keywords: Strain comparison
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.
Project description:Expression data from batch cultivations of Aspergillus niger wild type strain ATCC 1015 and adrA, facB and creA deletion mutants constructed on ATCC 1015 background strain with glucose or glycerol as carbon sources. Genome-wide transcriptome analysis was used to identify genes either affected directly or indirectly by each transcription factor investigated during growth on a repressing or a derepressing carbon source. For this purpose, batch cultivations under well-controlled conditions were performed with Aspergillus niger wild type strain ATCC 1015 and the three deletion mutants of the corresponding transcription factors AdrA, FacB and CreA. Samples for RNA extraction were collected and further processed for hybridization in custom-designed Affymetrix microarrays containing probes for three Aspergillus species, including A. niger.
Project description:The Aspergillus niger genome contains a large repertoire of genes encoding carbohydrate active enzymes (CAZymes) that are targeted to plant polysaccharide degradation enabling A. niger to grow on a wide range of plant biomass substrates. Which genes need to be activated in certain environmental conditions depends on the composition of the available substrate. Previous studies have demonstrated the involvement of a number of transcriptional regulators in plant biomass degradation and have identified sets of target genes for each regulator. In this study, a broad transcriptional analysis was performed of the A. niger genes encoding (putative) plant polysaccharide degrading enzymes. Microarray data focusing on the initial response of A. niger to the presence of plant biomass related carbon sources were analyzed of a wild-type strain N402 that was grown on a large range of carbon sources and of the regulatory mutant strains ΔxlnR, ΔaraR, ΔamyR, ΔrhaR and ΔgalX that were grown on their specific inducing compounds.
Project description:Transcriptional profiling of the A. niger WT (N402) strain treated with xylan (1%, w/v) for 6, 12 and 24 h. The main objective was to identify genes related to cellulases and hemicellulases after treatment with the polysaccharide xylan. The experiment was further validated by enzymatic assays.
Project description:This approach aims at searching unidentified regulatory roles of the AreB transcription factor in the overall carbon metabolism of A. niger. A full areB gene deletion mutant was constructed and characterized in A. niger ATCC 1015. Both strains were grown on glucose or glycerol using ammonia as nitrogen source in batch cultivations and the transcriptome was analyzed using three biological replicated transcriptome experiments. Two areB gene deletion replicates, one on glucose and one on glycerol were discarded due to bad quality and therefore not included in the analysis. Samples for RNA extraction were collected and further processed for hybridization in custom designed Affymetrix microarrays containing probes for three Aspergillus species including A. niger. Triplicate batch fermentations with the two Aspergillus niger strains used, the wild type A. niger strain ATCC 1015 and the areB complete gene deletion strain were carried out and transcriptome analysis was performed. Biomass from each batch cultivation was harvested in the exponential phase of growth and further processed for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Transcriptional profiling of A. niger comparing WT strain vs. ΔXlnR strain treated with steam-exploded sugarcane bagasse (SESB) for 6, 12 and 24 h. The main objective was to identifiy genes related to cellulases and hemicellulases, comparing the differences between WT strain and the strain with the disrupted xylanolytic transcriptional activator gene, XlnR, after treatment with steam-exploded sugarcane. The experiment was further validated by real-time PCR, mass spectrometry of secreted proteins and enzymatic assays.
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. We aim to discover differencial expressed genes in A.niger wild type strain N402 and M-NM-^TrhaR mutant while growing on rhamnose as carbon source. Biological duplicates were made for both strain at the growth of 2 hours, Affymetrix microarray experiments were performed on these samples.
