Project description:CRISPR interference screening of 129 protein kinases and 161 transcription factors in S. cerevisiae. Repression effects on yeast growth in oxygen-limited conditions were quantified in synthetic complete media (SCM), SCM supplemented with 10% lignocellulose hydrolysate and SCM supplemented with 45% of a mixture of growth-inhibiting lignocellulosic compounds. The aim of this project was to determine the reproducibility of CRISPRi effects across studies and to characterize CRISPRi for screening of phenotypes relevant for industrial biotechnology. We identify gene functions in general growth in oxygen-limited conditions, and specific for cellular fitness in lignocellulose hydrolysate. A further screen with a cocktail of lignocellulosic compounds enables us to explain hydrolysate-specific gene functions with roles in toxicity.
Project description:White-rot basidiomycete fungi are potent degraders of plant biomass with the ability to mineralize all lignocellulose components. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. In order to improve our understanding on the enzymatic mechanisms leading to lignocellulose breakdown, we analysed the early response of the white-rot fungus Pycnoporus coccineus CIRM-BRFM310 to various lignocellulosic substrates at two time points; Day 3 and Day 7.
Project description:Endophytic fungi are root-inhabiting fungi that can promote plant growth in a variety of ways. They can directly stimulate plant growth by producing phytohormones, such as auxin and gibberellins. They can also indirectly promote plant growth by helping plants to acquire nutrients, such as nitrogen and phosphorus, and by protecting plants from pests and pathogens.In this study, we used a proteomic approach to identify the proteins that are expressed in rice plants after they are treated with endophytic fungi. We found that the treatment with endophytic fungi resulted in the expression of a number of proteins involved in plant growth, nutrient acquisition, and defense. These results suggest that endophytic fungi can promote plant growth and improve plant resilience to stress.
Project description:Gaining new knowledge through fungal monoculture responses to lignocellulose is a widely used approach that can lead to better cocktails for lignocellulose saccharification (the enzymatic release of sugars which are subsequently used to make biofuels). However, responses in lignocellulose mixed cultures are rarely studied in the same detail even though in nature fungi often degrade lignocellulose as mixed communities. Using a dual RNA-seq approach, we describe the first study of the transcriptional responses of wild-type strains of Aspergillus niger, Trichoderma reesei and Penicillium chrysogenum in two and three mixed species shake-flask cultures with wheat straw. Based on quantification of species-specific rRNA, a set of conditions was identified where mixed cultures could be sampled so as to obtain sufficient RNA-seq reads for analysis from each species. The number of differentially-expressed genes varied from a couple of thousand to fewer than one hundred. The proportion of carbohydrate active enzyme (CAZy) encoding transcripts was lower in the majority of the mixed cultures compared to the respective straw monocultures. A small subset of P. chrysogenum CAZy genes showed five to ten-fold significantly increased transcript abundance in a two-species mixed culture with T. reesei. However, a substantial number of T. reesei CAZy transcripts showed reduced abundance in mixed cultures. The highly induced genes in mixed cultures indicated that fungal antagonism was a major part of the mixed cultures. In line with this, secondary metabolite producing gene clusters showed increased transcript abundance in mixed cultures and also mixed cultures with T. reesei led to a decrease in the mycelial biomass of A. niger. Significantly higher monomeric sugar release from straw was only measured using a minority of the mixed culture filtrates and there was no overall improvement. This study demonstrates fungal interaction with changes in transcripts, enzyme activities and biomass in the mixed cultures and whilst there were minor beneficial effects for CAZy transcripts and activities, the competitive interaction between T. reesei and the other fungi was the most prominent feature of this study.
Project description:The objective was to identify functional genes encoded by Fungi and fungal-like organisms to assess putative ecological roles Using the GeoChip microarray, we detected fungal genes involved in the complete assimilation of nitrate and the degradation of lignin, as well as evidence for Partitiviridae (a mycovirus) that likely regulates fungal populations in the marine environment. These results demonstrate the potential for fungi to degrade terrigenously-sourced molecules, such as permafrost and compete with algae for nitrate during blooms. Ultimately, these data suggest that marine fungi could be as important in oceanic ecosystems as they are in freshwater environments.
Project description:Endophytic fungi are fungi that live inside the roots of plants. They can promote plant growth through a variety of direct and indirect mechanisms. Direct mechanisms include the production of phytohormones, such as auxin and gibberellins, which can stimulate plant growth. Endophytic fungi can also fix nitrogen, solubilize phosphate, and produce siderophores, which are compounds that chelate iron and make it available to plants. In addition, some endophytic fungi produce antimicrobial metabolites that can protect plants from pests and pathogens. Indirect mechanisms include the induction of systemic resistance, which is a plant's ability to defend itself against pests and pathogens. Endophytic fungi can also help plants to tolerate abiotic stresses, such as drought, salinity, and heavy metals. In this study, we used a proteomic approach to identify the proteins that are expressed in rice plants after they are treated with endophytic fungi. We found that the treatment with endophytic fungi resulted in the expression of a number of proteins involved in plant growth, stress response, and defense. These results suggest that endophytic fungi can promote plant growth and improve plant resilience to stress.
Project description:Wood-degrading fungi play a critical role in global carbon cycling, and their varied mechanisms for deconstruction offer pathways for industrial bioconversion. In this study, we used comparative genomics to isolate upregulation patterns among fungi with brown rot (carbohydrate-selective) or white rot (lignin-degrading) nutritional modes. Specifically, we used whole-transcriptome profiling to compare early, middle, and late decay stages on wood wafers, matching differentially-expressed gene (DEG) patterns with fungal growth and enzyme activities. This approach highlighted 34 genes uniquely upregulated in early brown rot stages, with notable candidates involved in generating reactive oxygen species (ROS) as a pretreatment mechanism during brown rot. This approach further isolated 18 genes in late brown rot stages that may be adapted to handle oxidatively-reacted lignocellulose components. By summing gene expression levels in functional classes, we also identified a broad and reliable distinction in glycoside hydrolase (GH) versus lignocellulose oxidative (LOX) transcript counts that may reflect the energy investment burden of lignin-degrading machinery among white rot fungi.