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:Comparative genomics and transcriptomics of the filamentous fungi Aspergillus oryzae and Aspergillus niger have opened possibilities for investigating the cellular metabolism and regulation of these fungi on a systemic level. The aim of this work was to understand how metabolism is regulated and to identify common regulatory responses between A. oryzae and A. niger. We therefore conducted batch fermentations with A. oryzae and A. niger grown on three different carbon sources (glucose, maltose, and xylose) in order to investigate their genome-wide transcription response Keywords: Two Aspergillus species and different carbon sources
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:Comparative genomics and transcriptomics of the filamentous fungi Aspergillus oryzae and Aspergillus niger have opened possibilities for investigating the cellular metabolism and regulation of these fungi on a systemic level. The aim of this work was to understand how metabolism is regulated and to identify common regulatory responses between A. oryzae and A. niger. We therefore conducted batch fermentations with A. oryzae and A. niger grown on three different carbon sources (glucose, maltose, and xylose) in order to investigate their genome-wide transcription response Keywords: Two Aspergillus species and different carbon sources Three conditions (glucose, maltose and xylose) with three biological replicates for A. oryzae and A. niger
Project description:Aspergillus niger is a filamentous ascomycete fungus that is commonly found in most biotopes around the globe. In nature, A. niger degrades the plant biomass polysaccharides to monomeric sugars, transports them into the cells, and uses a variety of catabolic pathways to convert them into biochemical building blocks and energy. We show that when grown in liquid cultures, A. niger takes up plant-biomass derived monomeric sugars (and maltose) in a highly sequential manner, rather than simultaneously. Interestingly, this sequential uptake was not mediated by the fungal general carbon catabolite repressor protein CreA, which has been shown to mediate the use of preferential carbon sources over non-preferential carbon sources. Furthermore, transcriptome analysis strongly indicated that the preferential use of the monomeric sugars is arranged at the level of transport, but it is not reflected in transcriptional regulation of sugar catabolism. Therefore, the results indicate that the regulation of sugar transport and catabolism are separate physiological processes in 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:Aspergillus niger produces a variety of lignocellulolytic enzymes (cellulases, hemicellulases, among others) and is regarded as cell factory for the production of heterologous proteins. Therefore, there is a growing interest in the study of its genes and the understanding of the cellular mechanisms in order to expand its applications. On the other hand, we have shown that enzyme production by A. niger is higher when grown forming biofilms than when grown conventionally in submerged systems. The objective of this study was to perform a global transcriptomic analysis and an expression analysis of both lignocellulases and biofilm regulatory genes as compared to A. niger in submerged culture. DNA microarray assays were performed to investigate the global gene expression which yielded information on the expression of more than 90% of A. niger genes. To further this comparison, the two culture systems were supplemented with different carbon sources (glucose, lactose, xylose and maltose) to establish a differential gene expression under different culture conditions. Also, to validate the differential expression qPCR was performed for quantitative comparison of the transcriptional level of genes in both culture systems. Organism : Aspergillus niger, Agilent Aspergillus niger Gene expression 4x44k Array AMADID: 032510 Grant Information: Grant Nº 072-FINCyT-PIN2008 from the National Program of Science and Technology of Peru Contributor: Institut Pasteur de Montevideo, Uruguay
Project description:To study the induction of the genes encoding known and putative enzymes from the pectinolytic system of A. niger, the transcriptional profiles of 58 selected known or putative pectinolytic genes were monitored by microarray experiments. For this purpose, A. niger was cultivated on the complex substrates, sugar beet pectin and polygalacturonic acid as primary carbon sources. Galacturonic acid, rhamnose and xylose were used to assess the effects on gene expression caused by simple well-defined carbon sources, representing the most abundant sugar residues present in the backbone of pectin. Fructose, as a strong repressor of the expression of genes that are under carbon catabolite regulation, and sorbitol, as a non-inducing sugar-like alcohol, which does not affect the carbon catabolite regulation mechanisms were selected as control substrates. Mycelia of A. niger were pregrown for 18 h on 2% fructose, transferred to medium containing the different pectic and control substrates, and sampled at four time points during 24 h of incubation.
Project description:Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that over a third of the genes induced after 6 h of exposure to wheat straw were also induced during 6 h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides. Eight samples in total consisting of duplicate shake flask Aspergillus niger cultures from four conditions: 48h glucose, 6 h starvation, 6 h wheat straw, 24 h starvation
Project description:This SuperSeries is composed of the following subset Series: GSE37758: Aspergillus niger : Control (fructose) vs. steam-exploded sugarcane induction (SEB) GSE37760: Aspergillus niger : Control (fructose) vs. xylose + arabinose (XA) Refer to individual Series