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: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. Triplicate batch fermentations of each of the four Aspergillus niger strains used, the wild type A. niger strain ATCC 1015 and three gene deletion mutants, were carried out using glucose or glycerol as carbon source, 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: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: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: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.
Project description:A. niger and A. oryzae are two filamentous fungi widely used in industry to produce various enzymes (e.g. pectinases, amylases) and metabolites (e.g. citric acid). Using proteomics, the co-cultivation of these two fungi in wheat bran showed an equal distribution of the two strains forming mixed colonies with a broad range of carbohydrate active enzymes produced. This stable mixed microbial system seems suitable for subsequent commercial processes such as enzyme production. XlnR knock-out strains for both aspergilli were used to study the influence of plant cell wall degrading enzyme production on the fitness of the mixed culture.
Project description:Transcriptomics was performed on batch cultivations of A. niger grown on three monosaccharides and three complex carbohydrates with defined compositions as to allow the detection of cross-induction if present, and for demonstration of how enzyme interaction graphics can be used to visualize the global transcription response.
Project description:The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, for which it is equipped with a range of enzyme systems. A significant proportion of plant material are lipids that might be available either as for energy storage or as membrane building blocks. With 63 potential lipase-encoding genes in its genome, A. niger has the tools to degrade these extracellular lipids. In contrast to polysaccharide-degrading enzyme networks not much is known about the signalling and regulatory processes that control lipase expression and activity in fungi both under laboratory and natural occurring conditions. A pulse of 1 mM of various oils was applied to four bioreactor-grown A. niger cultures to examine (i) whether A. niger responds at the level of gene transcription, (ii) at what time point this effect is detected most accurately, and (iii) whether differences between the response towards oils are observed. The triglyceride olive oil induces genes encoding peroxins and enzymes of fatty acid metabolism. A complex oil mixture extracted from wheat gluten, which is enriched for digalactosyl-diglycerides, induces genes encoding peroxins as well as enzymes of fatty acid metabolism, but with different expression profile when compared to olive oil. Pure digalactosyldiglyceride, a proxy for plant membrane lipids, does not trigger a transcriptional response. Keywords: time course; induction experiment
Project description:Oxygen limitation is regarded as a useful strategy to improve enzyme production by mycelial fungus like Aspergillus niger. However, the intracellular metabolic response of A. niger to oxygen limitation is still obscure. To address this, the metabolism of A. niger was studied using multi-omics integrated analysis based on the latest GEMs (genome-scale metabolic model), including metabolomics, fluxomics and transcriptomics. Upon sharp reduction of the oxygen supply, A. niger metabolism shifted to higher redox level status, as well as lower energy supply, characterized by the accumulation of intermediates from the TCA cycle, down-regulation of genes for fatty acid synthesis and a rapid decrease of the specific growth rate. The gene expression of the glyoxylate bypass was activated, consistent with the increasing flux, which was assumed to reduce the NADH formation from TCA cycle and benefit maintenance of the cellular redox balance under hypoxic conditions. In addition, the relative fluxes of the EMP pathway were increased, which possibly relieved the energy demand for cell metabolism.