Chemostat Array
Ontology highlight
ABSTRACT:
ORGANISM(S): Aspergillus fumigatus
SUBMITTER: Bridget Barker
PROVIDER: E-MEXP-3251 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Low oxygen conditions are not only common to natural environments but also occur during tissue invasive growth in the human host. Only few cellular factors have been identified up to now that allow the fungus to efficiently adapt its energy metabolism to the lack of O2. In the present study, we cultivated A. fumigatus in an O2-controlled fermenter and analysed its minute-scale responses to O2 limitation. Transcriptome sequencing revealed a group of genes underlying a rapid and highly dynamic regulation. As an initial experimental setup, A. fumigatus was cultivated in an O2-controlled fermenter, which allowed minute-scale variations in O2-fluxes largely independent of other secondary effects. Cultures were initially grown at saturated O2 concentrations (100% saturation M-bM-^IM-^H 260 M-BM-5mol l-1) and rapidly shifted to hypoxic growth conditions at an initial O2 saturation of 5% (M-bM-^IM-^H 13 M-BM-5mol l-1). Dynamics of low and high O2 responses of A. fumigatus cultivated in an O2-controlled fermenter
2014-07-25 | E-GEOD-55943 | biostudies-arrayexpress
Project description:Renewables-based biotechnology depends on enzymes to degrade plant lignocellulose to simple sugars that are converted to fuels or high-value products. Identification and characterization of such lignocellulose degradative enzymes could be fast-tracked by availability of an enzyme activity measurement method that is fast, label-free, uses minimal resources and allows direct identification of generated products. We developed such a method by applying carbohydrate arrays coupled with MALDI-ToF mass spectrometry to identify reaction products of carbohydrate active enzymes (CAZymes) of the filamentous fungus Aspergillus niger. We describe the production and characterization of plant polysaccharide-derived oligosaccharides and their attachment to hydrophobic self-assembling monolayers on a gold target. We verify effectiveness of this array for detecting exo- and endo-acting glycoside hydrolase activity using commercial enzymes, and demonstrate how this platform is suitable for detection of enzyme activity in relevant biological samples, the culture filtrate of A. niger grown on wheat straw. In conclusion, this versatile method is broadly applicable in screening and characterisation of activity of CAZymes, such as fungal enzymes for plant lignocellulose degradation with relevance to biotechnological applications as biofuel production, the food and animal feed industry.
2018-10-26 | PXD005699 | Pride
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
2014-08-22 | E-GEOD-57315 | biostudies-arrayexpress
Project description:Hyphae and conidia, representing the two developmental stages of the fungus, were examined separately in this study.<br><br>RNA from hyphae or conidia incubated in plasma in RPMI/HEPES without neutrophils was used as reference, and was co-hybridized with the query samples obtained from the corresponding sets incubated with neutrophils.<br><br>Each biological replicate was carried out with neutrophils obtained from a different donor, and the RNA samples associated with each neutrophil source was paired separately with a corresponding reference sample prepared at the same time.<br><br>
2008-09-25 | E-MEXP-1722 | biostudies-arrayexpress
Project description:Aspergillus fumigatus is the most important pulmonary fungal pathogen. Virulence has evolved several times in the section Aspergillii. However, there are species in this section, such as A. fischerii and A. oerlinghausensis, that are very closely related to A. fumigatus but are not reported as pathogens. By using trypsin shaving, we have identified the proteins on the conidial surface of conidia and swollen conidia of A. fumigatus, A. fischeri, A. oerlinghausensis, and A. lentulus. We have identified about 900 proteins in all four species and shown 52 that are unique in A. fumigatus. Both A. fischerii and A. oerlinghausensis have homologues for most of these proteins. However, they are not expressed in the conidia and and could reflect specific A. fumigatus traits important for infection and/or immune evasion.
2024-06-26 | PXD031199 | Pride
Project description:An Aspergillus fumigatus infection is initialized by the inhalation and germination of airborne asexual spores (conidia). Alveolar macrophages are the first immune cells to counteract an infection by phagocytosis of conidia and intracellular degradation of the pathogen. However, A. fumigatus circumvents its intracellular killing by the manipulation of the phagolysosomal maturation. With a comparative proteomic study of the phagolysosomal proteome of a virulent wild type A. fumigatus strain and an avirulent mutant strain we aimed at the identification of proteins and processes that are hijacked by the virulent strain. We found that wild type conidia strongly modulate the protein composition of the phagolysosome. Assembly and activity of vATPase, formation of lipid rafts, signal transduction pathways as well as the generation of energy and metabolites were significantly regulated in the wild type conidia containing phagolysosomes. In different experimental setups we confirmed a disassembly of the vATPase complex, reduced formation of lipid rafts and altered abundances of mTOR, MAPK signaling molecules, Rab5 and Vamp8 mediators of endosomal trafficking as well as LAMP1 and cathepsin Z lysosomal markers. Our interactome analysis indicates that A. fumigatus proteins target small GTPases of the endosomal trafficking system and signal transducers of the host, which might lead to a reduced fungicidal activity of the phagolysosome.
2018-03-08 | PXD005724 | Pride
Project description:Gene expression analysis of four different treatments of Aspergillus nidulans. reference line (A.nidulans), line A (A.nidulans + Streptomyces rapamycinicus), line B (A.nidulans + orsellinic acid), line C (A.nidulans + lecanoric acid) For each of these treatments 2 biological replicates were made.
2011-05-25 | E-GEOD-25266 | biostudies-arrayexpress
Project description:Aspergillus fumigatus mutant strains were collected from bronchoalveolar lavage fluids (BALFs) during acute mouse infection (4 and 12 hours). Transcriptional analysis were conducted by comparison of each mutant with the wild type strain (CEA17) in a dye swap experiment. Besides, we performed the transcriptional profile of akuB(KU80) mutant compared to CEA17 wild type strain. All the strains were recovered from bronchoalveolar lavage fluid from CD1 mice infected with 10e8 spores for 4 and 12 hours.
2012-12-02 | E-GEOD-27428 | biostudies-arrayexpress
Project description:Experimental evolution was conducted using Drosophila melanogaster populations that developed as larvae on breeding substrate that was infested with Aspergillus nidulans wild type, A. nidulans toxin-impaired mutant strain delta-laeA, the mycotoxin sterigmatocystin, or on fungi and toxin free substrate. Overall population were reared under these conditions for 11 generations, where after each confrontation generation one relaxation generation (fungi and toxin free breeding substrate) was conducted. Nine generations after the last selection treatment, first instar larvae were confronted with 3 days old A. nidulans wild type colonies or control conditions. 24 hours after confrontation start larvae were collected. For each biological replicate 52 larvae were collected from 4 independent confrontation units, balanced design. Three populations per selection regime were conducted, resulting in: 2 conditions x 4 selection regimes x 3 biological replicates (equal to fly population) = 24 samples. Selection regimes: sCO= control; sWT= A. nidulans wild type; sLA= A. nidulans mutant strain; sST= Sterigmatocystin. confrontation condition: cCO= control; cWT= A. nidulans wild type.
2020-05-09 | E-MTAB-9011 | biostudies-arrayexpress
Project description:Aspergillus fumigatus is an opportunistic, airborne pathogen causing invasive aspergillosis in immunocompromised patients. During the infection process A. fumigatus is challenged by hypoxic microenvironments occurring in inflammatory, necrotic tissue. To gain further insights into the adaptation mechanism, A. fumigatus was cultivated in an oxygen-controlled chemostat under hypoxic and normoxic conditions. Transcriptome analysis revealed significant increases in transcripts associated with cell wall polysaccharide metabolism, amino acid and metal ion transport, nitrogen metabolism and glycolysis. A concomitant reduction in transcript levels was observed with cellular trafficking and G-protein coupled signaling. To learn more about the functional roles of hypoxia-induced transcripts we deleted A. fumigatus genes putatively involved in reactive nitrogen species detoxification (fhpA), NAD+ regeneration (frdA, osmA) nitrogen metabolism (niaD, niiA) and respiration (rcfB). We show that the NO-detoxifying flavohemoprotein fhpA is strongly induced by hypoxia independent of the nitrogen source, but is dispensable for hypoxic survival. By deleting the nitrate reductase gene niaD, the nitrite reductase gene niiA and the two fumarate reductases genes frdA and osmA, we found that alternative electron acceptors such as nitrate and fumarate do not have a significant impact on growth of A. fumigatus during hypoxia, but that functional mitochondrial respiratory chain complexes are essential under these conditions. Inhibition studies indicated that primarily complex III and IV play a crucial role in the hypoxic growth of A. fumigatus.
2014-07-01 | E-MTAB-2699 | biostudies-arrayexpress