Project description:We have examined and compared the transcriptome of T. reesei growing on wheat straw and lactose as carbon sources under otherwise similar conditions. Gene expression on wheat straw exceeded that on lactose, and 1619 genes were found to be only induced on wheat straw but not on lactose. They comprised 30 % of the CAZome, but were also enriched in genes associated with phospholipid metabolism, DNA synthesis and repair and iron homeostatis. Two thirds of the CAZome was expressed both on wheat straw as well as on lactose, but 60 % of it at least >2-fold higher on the former. Major wheat straw specific genes comprised xylanases, chitinases and ß-mannosidases. Interestingly, the latter two CAZyme families were significantly higher expressed in a strain in which xyr1 encoding the major regulator of cellulase and hemicellulase biosynthesis is non-functional, demonstrating that XYR1 is a repressor of these genes.
Project description:We have examined and compared the transcriptome of T. reesei growing on wheat straw and lactose as carbon sources under otherwise similar conditions. Gene expression on wheat straw exceeded that on lactose, and 1619 genes were found to be only induced on wheat straw but not on lactose. They comprised 30 % of the CAZome, but were also enriched in genes associated with phospholipid metabolism, DNA synthesis and repair and iron homeostatis. Two thirds of the CAZome was expressed both on wheat straw as well as on lactose, but 60 % of it at least >2-fold higher on the former. Major wheat straw specific genes comprised xylanases, chitinases and M-CM-^_-mannosidases. Interestingly, the latter two CAZyme families were significantly higher expressed in a strain in which xyr1 encoding the major regulator of cellulase and hemicellulase biosynthesis is non-functional, demonstrating that XYR1 is a repressor of these genes. We used two biological replicas of four T. reesei strains growing on glucose, lactose, and on wheat straw
Project description:A molecular cartography workflow was used to visualize the spatial distribution of paraisariamides in a lyophilized specimen of a beetle larva parasitized by P. insignis. These heptapeptides were localized to the beetle larva host and fungal endosclerotium inside the larva, consistent with a role in disrupting eukaryotic protein synthesis. LCMS2 data were acquired for 120 samples. Excisions of approximately 1-5 mg of material were made from points on the insect-fungus specimen corresponding to each of the sample points and annotated for the tissue of origin either as fertile portion of the fruiting body (FP), sterile portion of the fruiting body (St), rhizomorphs (Rz), larva exoskeleton (Ex), larva cuticle (Cu), smooth hyphae (Sm), endosclerotium (En), or a combination of two of these tissues.
Project description:Background: Saprobic fungi are the predominant industrial sources of Carbohydrate Active enZymes (CAZymes) used for the saccharification of lignocellulose during the production of second generation biofuels. The production of more effective enzyme cocktails is a key objective for efficient biofuel production. To achieve this objective, it is crucial to understand the response of fungi to lignocellulose substrates. Our previous study used RNA-seq to identify the genes induced in Aspergillus niger in response to wheat straw, a biofuel feedstock, and showed that the range of genes induced was greater than previously seen with simple inducers [GSE33852]. Results: In this work we used RNA-seq to identify the genes induced in A. niger in response to short rotation coppice willow and compared this with the response to wheat straw from our previous study, at the same time-point. The response to willow showed a large increase in expression of genes encoding CAZymes. Genes encoding the major activities required to saccharify lignocellulose were induced on willow such as endoglucanases, cellobiohydrolases and xylanases. The transcriptome response to willow had many similarities with the response to straw with some significant differences in the expression levels of individual genes which are discussed in relation to differences in substrate composition or other factors. Differences in transcript levels include higher levels on wheat straw from genes encoding enzymes classified as members of GH62 (an arabinofuranosidase) and CE1 (a feruloyl esterase) CAZy families whereas two genes encoding endoglucanases classified as members of the GH5 family had higher transcript levels when exposed to willow. There were changes in the cocktail of enzymes secreted by A. niger when cultured with willow or straw. Assays for particular enzymes as well as saccharification assays were used to compare the enzyme activities of the cocktails. Wheat straw induced an enzyme cocktail that saccharified wheat straw to a greater extent than willow. Genes not encoding CAZymes were also induced on willow such as hydrophobins as well as genes of unknown function. Several genes were identified as promising targets for future study. Conclusions: By comparing this first study of the global transcriptional response of a fungus to willow with the response to straw, we have shown that the inducing lignocellulosic substrate has a marked effect upon the range of transcripts and enzymes expressed by A. niger. The use by industry of complex substrates such as wheat straw or willow could benefit efficient biofuel production.
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:In this study, a complex microbial community from a semi-continues reactor, which only substrate is wheat straw, was incubated in a batch experiment with 13C-cellulose. protein stable isotope probing (protein-SIP) was used to identify the organisms, at high taxonomic resolution, involved in the degradation of cellulose by tracking the incorporation of 13C in the newly synthetized proteins. Thereby providing information regarding identity and function simultaneously and enable the optimization of biotechnologies for biofuels production.
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.