Aspergillus niger : Control (fructose) vs. xylose + arabinose (XA)
Ontology highlight
ABSTRACT:
ORGANISM(S): Aspergillus niger
PROVIDER: GSE37760 | GEO | 2012/05/07
SECONDARY ACCESSION(S): PRJNA163659
REPOSITORIES: GEO
Similar Datasets
Project description:Transcriptional profiling of A. niger comparing different strains (WT, M-NM-^TXlnR, M-NM-^TaraR and M-NM-^TaraRM-NM-^TXlnR) treated with 25mM xylose + 25mM arabinose for 2 and 8h. The main objective was to identifiy genes related to primary metabolism and carbohydrate metabolism in general, for instance, cellulases and hemicellulases. The study will compare the differences between WT strain and the strains with the disrupted xylanolytic transcriptional activator gene, XlnR, the arabinolytic transcriptional activator gene, AraR, and the double mutant,after treatment with xylose+arabinose (XA treatment). The experiment was further validated by real-time PCR and enzymatic assays. Two-condition experiment : A. niger mutant strains on XA for 2 and 8 h at 30 oC in batch culture. Firstly, the strains were pre-grown in minimal medium with fructose as carbon source (control), and then transferred to xylose+arabinose (25 mM each) as carbon source.
2012-05-06 | E-GEOD-37760 | biostudies-arrayexpress
Project description:Transcriptional profiling of A. niger comparing mutant strains with the disrupted xylanolytic transcriptional activator gene, XlnR, the arabinolytic transcriptional activator gene, AraR, and the double mutant (ΔXlnR, ΔaraR and ΔaraRΔXlnR, repsectively) treated with steam-exploded sugarcane bagasse (SEB) for 12 and 24 h. The main objective was to identify genes related to cellulases and hemicellulases in mutant strains grown on SEB, with indirect comparisons with the WT strain grown on SEB [the (WT/SEB) data deposited in GSE24798]. The experiment was further validated by real-time PCR and enzymatic assay.
2012-05-07 | GSE37758 | GEO
Project description:Transcriptional profiling of A. niger comparing mutant strains with the disrupted xylanolytic transcriptional activator gene, XlnR, the arabinolytic transcriptional activator gene, AraR, and the double mutant (M-NM-^TXlnR, M-NM-^TaraR and M-NM-^TaraRM-NM-^TXlnR, repsectively) treated with steam-exploded sugarcane bagasse (SEB) for 12 and 24 h. The main objective was to identify genes related to cellulases and hemicellulases in mutant strains grown on SEB, with indirect comparisons with the WT strain grown on SEB [the (WT/SEB) data deposited in GSE24798]. The experiment was further validated by real-time PCR and enzymatic assay. Two-condition experiment : A. niger mutant strains on SEB for 12 and 24 h at 30 oC in batch culture. Firstly, the strains were pre-grown in minimal medium with fructose as carbon source (control), and then transferred to SEB as carbon source.
2012-05-06 | E-GEOD-37758 | biostudies-arrayexpress
Project description:Transcriptional profiling of A. niger comparing WT strain vs. ÎXlnR 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. Three-condition experiment : WT-SESB or ÎXlnR-SESB for 6, 12 and 24 h at 30 oC in batch culture. Firstly, WT and ÎXlnR strains were grown in minimal medium with fructose as carbon source (control), and then transferred to SESB as carbon source.
2010-10-20 | E-GEOD-24798 | biostudies-arrayexpress
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.
2010-10-20 | GSE24798 | GEO
Project description:In this study we identified the L-arabinose-responsive regulator of Pyricularia oryzae that regulates L-arabinose release and catabolism. Previously we identified the Zn2Cys6 transcription factor (TF) AraR that has this role in the Trichocomaceae family (Eurotiales), but is absent in other fungi. Candidate Zn2Cys6 TF genes were selected according to their transcript profiles on L-arabinose. Deletion mutants of these genes were screened for their growth phenotype on L-arabinose. One mutant, named Δara1, was further analyzed. Our analysis demonstrated that Ara1 from P. oryzae is the functional homolog of AraR from A. niger, while sequence analysis did not reveal significant homology between them.
2016-11-11 | GSE74916 | GEO
Project description:Aspergillus niger is a filamentous fungus well known for its ability to produce a wide variety of pectinolytic enzymes, which have many applications in the industry. The transcriptional activator GaaR is induced by 2-keto-3-deoxy-L-galactonate, a compound derived from D-galacturonic acid, and plays a major role in the regulation of pectinolytic genes. The requirement for inducer molecules can be a limiting factor for the production of enzymes. Therefore, the generation of chimeric transcription factors able to activate the expression of pectinolytic genes by using underutilized agricultural residues would be highly valuable for industrial applications. In this study, we used the CRISPR/Cas9 system to generate three chimeric GaaR::XlnR transcription factors by swapping the N-terminal region of the xylanolytic regulator XlnR to that of the GaaR in A. niger. As a test case, we constructed a PpgaX:hph reporter strain to evaluate the alteration of transcription factor specificity in the chimeric mutants. Additionally, we generated a constitutively active GaaR::XlnR V756F version of the most efficient chimeric transcription factor to better assess its activity. Our results showed that the chimeric GaaR::XlnR transcription factor was no longer induced in the presence of D-galacturonic acid, but in the presence of D-xylose instead. Moreover, proteomics analysis and saccharification assays confirmed the production of enzymes involved in the release of L-arabinose from pectin, while the constitutive version of this chimeric transcription factor showed consistently improved D-galacturonic acid release from pectin in a gaaR deletion background.
2021-11-18 | PXD025383 | Pride
Project description:Hemicellulose, the second most abundant plant biomass fraction after cellulose, is widely viewed as a potential feedstock for the production of liquid fuels and other value-added materials. Degradation of hemicellulose by filamentous fungi requires production of many different enzymes, which are induced by biopolymers or its derivatives and regulated mainly at the transcriptional level through transcription factors (TFs). Neurospora crassa has been shown to express and secrete plant cell wall associated enzymes. To better understand genes specifically associated with degradation of hemicellulose, we identified 353 genes by transcriptome analysis of N. crassa wild type strain grown on beechwood xylan. Exposure to xylan induces 9 of the 19 predicted hemicellulase genes. The xylanolytic phenotype of strains with deletions in genes identified from the secretome and transcriptome analysis of wild type showed that none were essential for growth on beechwood xylan. The transcription factor XlnR/Xyr1 in Aspergillus and Trichoderma species is considered to be the major transcriptional regulator of genes encoding both cellulases and hemicellulases. We identified a xlnR/xyr1 homolog in N. crassa, NCU06971, termed xlr-1 (xylanase regulator 1). Deletion of xlr-1 in N. crassa abolishes the growth on xylan and xylose, but growth on cellulose was indistinguishable from wild type. To determine regulatory mechanisms associated with hemicellulose degradation, we explored the transcriptional regulon of XLR-1 under xylose and xylanolytic versus cellulolytic conditions. XLR-1 regulated only some predicted hemicellulase genes in N. crassa and was required for a full induction of several cellulase genes. Hemicellulase gene expression was induced by a combination of release from carbon catabolite repression (CCR) and induction. However, in N. crassa, xlr-1 is subject to non-CRE-1 mediated CCR. This systematic analysis provides the similarities and differences of hemicellulose degradation and regulation mechanisms used by N. crassa in comparison to other filamentous fungi. Four-condition experiments (minimal medium, xylan medium,xylose and Avicel medium) of mutant strain(xlr-1) compared to wild type strain; Cy3 and Cy5 dye swap
2012-03-26 | E-GEOD-34098 | biostudies-arrayexpress
Project description:Background: Bacterial fermentation of carbohydrates from sustainable lignocellulosic biomass into biofuels by the anaerobic bacterium Clostridium acetobutylicum is a promising alternative energy source to fossil fuels. Understanding the complex metabolic pathways it employs and how they are regulated will contribute to improved biofuel production. Recently, it has been demonstrated that xylose is not appreciably fermented in the presence of arabinose, suggesting a hierarchy of pentose utilization in this organism. Our goal is to uncover if transcriptional regulation contributes to this hierarchy. Results: Growth and sugar consumption rates showed that arabinose, like glucose, actively represses xylose utilization in cultures fermenting xylose. RNA-Seq revealed there was a large overlap in differentially regulated genes after addition of arabinose or glucose, suggesting a common mechanism of regulation. A putative ORF was identified that may be important for transcriptional regulation in response to the nutritional state of the cells. Conclusions: Decreased xylose consumption, increased acetate production, and transcription of the phosphoketolase gene (CA_C1343) revealed a transition of pentose catabolism from the pentose phosphate pathway to the phosphoketolase pathway after addition of arabinose. Together, these results substantiate the claim that arabinose is utilized preferentially over xylose in C. acetobutylicum. Furthermore, they demonstrate that this phenomenon is modulated in part at the transcriptional level, and they provide valuable insight into potential mechanisms for altering pentose utilization to modulate fermentation products for biofuel production.
2017-12-20 | GSE107804 | GEO
Project description:The transcriptional activator XlnR (Xlr1/Xyr1) is a major regulator in fungal xylan and cellulose degradation as well as in the utilization of d-xylose via the pentose catabolic pathway. XlnR homologs are commonly found in filamentous ascomycetes and often assumed to have the same function in different fungi. However, a comparison of the saprobe Aspergillus niger and the plant pathogen Magnaporthe oryzae showed different phenotypes for deletion strains of XlnR. In this study wild type and xlnR/xlr1/xyr1 mutants of five fungi were compared: Fusarium graminearum, M. oryzae, Trichoderma reesei, A. niger and Aspergillus nidulans. Growth profiling on relevant substrates and a detailed analysis of the secretome as well as extracellular enzyme activities demonstrated a common role of this regulator in activating genes encoding the main xylanolytic enzymes. However, large differences were found in the set of genes that is controlled by XlnR in the different species, resulting in the production of different extracellular enzyme spectra by these fungi. This comparison emphasizes the functional diversity of a fine-tuned (hemi-)cellulolytic regulatory system in filamentous fungi, which might be related to the adaptation of fungi to their specific biotopes.
2014-08-01 | PXD001190 | Pride