Combinatorial control of gene expression in Aspergillus niger grown on sugar beet pectin
Ontology highlight
ABSTRACT:
ORGANISM(S): Aspergillus niger
PROVIDER: GSE97974 | GEO | 2017/11/09
SECONDARY ACCESSION(S): PRJNA383547
REPOSITORIES: GEO
Similar Datasets
Project description:Aspergillus niger produces an arsenal of extracellular enzymes that allow synergistic degradation of plant biomass found in its environment. Pectin is a heteropolymer abundantly present in the primary cell wall of plants. The complex structure of pectin requires multiple enzymes to act together. Production of pectinolytic enzymes in A. niger is highly regulated, which allows flexible and efficient capture of nutrients. So far, three transcriptional activators have been linked to regulation of pectin degradation in A. niger. The L-rhamnose-responsive regulator RhaR controls the production of enzymes that degrade rhamnogalacturonan-I. The L-arabinose-responsive regulator AraR controls the production of enzymes that decompose the arabinan and arabinogalactan side chains of rhamnogalacturonan-II. The D-galacturonic acid-responsive regulator GaaR controls the production of enzymes that act on the polygalacturonic acid backbone of pectin. This project aims to better understand how RhaR, AraR and GaaR co-regulate pectin degradation. For that reason, we constructed single, double and triple disruptant strains of these regulators and analyzed their growth phenotype and pectinolytic gene expression in A. niger grown on sugar beet pectin.
| S-EPMC5617896 | biostudies-other
Project description:In this study, we compared the gene expression pattern of A. niger grown in liquid sugar beet pulp (SBP) at different time points, a by-product of the sugar industry that consists mainly of cellulose, xyloglucan, and pectin. Finally, we compared A. niger genetic response to liquid SBP to that of the same fungus when grown on solid SBP plates and polygalacturonic acid (PGA).
2021-08-04 | GSE175954 | GEO
Project description:Filamentous fungi are ubiquitous organisms and major plant biomass degraders. As a single colony, some fungal species can colonize large areas as up to five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a main determinant of spatial gene expression in colonies of Aspergillus niger. This question was addressed by analyzing whole-genome gene expression in five concentric zones of 5-day-old sugar beet pulp grown colonies. Growth, protein production and secretion were occurring throughout the whole colony. Carbon and nitrate utilization were constant from the centre to the periphery whereas genes encoding plant cell wall degrading enzymes were expressed with a different pattern across the colony. Finally our results demonstrate a fine-tuning of the different enzymatic tools available in A. niger and expand the knowledge on how this fungus adapts as it colonizes complex environments.
2016-03-04 | GSE66641 | GEO
Project description:Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia.During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism and nitrate utilization were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate a fine-tuning of the different enzymatic tools available in A. niger and reveal how this fungus adapts as it colonizes complex environments.
2015-09-09 | PXD002130 | Pride
Project description:Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes and nitrate utilization were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate that A. niger employs different enzymatic tools to adapt its metabolism as it colonizes complex environments.
| S-EPMC4552001 | biostudies-literature
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.
2008-06-13 | E-MEXP-1626 | biostudies-arrayexpress
Project description:Transcriptional profiling of A. niger comparing different strains (WT, ΔXlnR, ΔaraR and ΔaraRΔXlnR) 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.
2012-05-07 | GSE37760 | GEO
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