Project description:Background: Wood-decay basidiomycetes are effective for the degradation of highly lignified and recalcitrant substrates. Brown-rot strain produces carbohydrate-active enzymes involved in the degradation of lignocellulosic materials, along with a non-enzymatic mechanism, via Fenton reaction. Differences in the lignocellulose metabolism occurring even among closely related brown-rots are not completely understood, bringing attention to a multi-omics study of brown-rot L. sulphureus. Results: To evidence the oxidative-hydrolytic mechanism, the Laetiporus sulphureus ATCC 52600 genome was sequenced and the response to lignocellulosic substrates was analyzed by transcriptomics and proteomics. The transcriptomic profile in response to a short cultivation period on in natura sugarcane bagasse revealed 128 out of 12,802 upregulated transcripts. The high upregulated transcripts included a set of redox enzymes along with hemicellulases. The exoproteome in response to extended-time cultivation with Avicel, and steam-exploded sugarcane bagasse, sugarcane straw, and Eucalyptus grandis revealed 121 proteins. Contrasting to the mainly oxidative profile observed in the transcriptome, the secretomes showed a diverse hydrolytic repertoire including constitutive cellulases and hemicellulases, in addition to 19 proteins upregulated relative to glucose. The secretome produced on sugarcane bagasse was evaluated in the saccharification of pretreated sugarcane straw by supplementing a commercial cocktail. Additionally, growth analysis revealed that L. sulphureus ATCC 52600 has higher efficiency to assimilate glucose than other mono and disaccharides. Conclusion: This study shows the singularity of L. sulphureus ATCC 52600 relative to other Polyporales brown-rots, regarding the presence of cellobiohydrolase and peroxidase class II. The multi-omic analysis reinforces the oxidative-hydrolytic metabolism involved in lignocellulose deconstruction, providing insights into the overall mechanisms as well as specific proteins of each step.
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.
Project description:Metaproteomic analysis of an enriched anaerobic rumen consortium (ERAC) using sugarcane bagasse and rumen as unique carbon and microbial sources
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.
Project description:The phytopathogenic fungus Chrysoporthe cubensis is a relevant source of lignocellulolytic enzymes. This work aimed to compare the profile of lignocellulose- degrading proteins secreted by C. cubensis grown under semi-solid state fermentation using wheat bran and sugarcane bagasse. The proteins from the fungus extract grown in wheat bran (WBE) and sugarcane bagasse (SBE) were qualitative and quantitatively analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS). Label-free proteomic analysis of WBE and SBE showed that the fungus produced a spectrum of carbohydrate-active enzymes (CAZymes) with exclusive characteristics from each extract. While SBE resulted in an enzymatic profile directed towards the depolymerization of cellulose, the enzymes in WBE were more adaptable to the degradation of biomass rich in hemicellulose and other non-lignocellulosic polymers. Saccharification of alkaline pre-treated sugarcane bagasse with SBE promoted glucose release higher than commercial cocktails (8.11 g L -1 ), while WBE promoted the higher release of xylose (5.71 g L -1 ). Our results allowed an in-depth knowledge of the complex set of enzymes secreted by C. cubensis responsible for its high lignocellulolytic activity and still provided the identification of promising target proteins for biotechnological applications in the context of biorefinery.
Project description:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
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.