Project description:A laboratory colony of Phlebotomus perniciosus sand flies was maintained. Sand flies were infected with cultured Leishmania infantum promastigotes in stationary phase. Ten infected sand flies were dissected after 5 days and promastigotes within the gut pooled. The cells were immediately washed in PBS once and lysed in TRIzol reagent (Life Technologies). RNA isolation was completed according to the manufacturer's instructions, obtaining 63ng. RNA-seq libraries were generated using the spliced leader sequence for second strand synthesis (Cuypers et al., 2017; Haydock et al., 2015), thus allowing for specific amplification of sequences from L. infantum promastigotes, thus avoiding contamination with material from the sand fly gut. Single-end sequencing was performed in an Illumina HiSeq2500 instrument and data analysis was conducted using bowtie2, samtools, featureCounts and Geneious. The main findings are: i) substantial differences in differential gene expression between sand fly-derived (sfPro) and cultured (acPro) promastigotes; and ii) over-expression of genes involved in metacyclogenesis in sfPro vs. acPro, including gp63 genes, autophagy genes, etc.
Project description:Herbivorax saccincola A7 is an alkali-thermophilic lignocellulolytic bacterium that was known to possess a strong xylan degradation ability. They can utilize a wide range of carbon sources, however the response and regulation mechanisms to different carbon sources, in terms of genes expression, are still not identified. In this study, H. saccincola A7 was cultured with cellobiose, cellulose, xylan, cellulose-xylan mixture, and empty fruit bunch (EFB) as the sole carbon source. We carried out a comparative expression analysis, focusing on biomass degradation-related genes. The cellulosomal scaffolding proteins and cellulosomal enzymes of H. saccincola A7 were drastically induced when a cellulose-containing substrate was used as a carbon source. On the other hand, xylan induced only some non-cellulosomal enzymes that might be necessary for xylan degradation. The identification of the carbohydrate-sensing mechanism in H. saccincola A7 appeared a similar system as previously described in Clostridium thermocellum. The lignocellulose degradation ability of H. saccincola A7 may be controlled enzyme expression by cellulose-containing substrate, not by xylan. Thus, recognition in the existence of cellulosic substrates is effective in enhancing a high xylan degradation ability in H. saccincola A7.
Project description:Microbial deconstruction of plant polysaccharides is important for environmental nutrient cycling, and bacteria proficient at this process have extensive suites of polysaccharide-specific enzymes. In the Gram-negative saprophyte Cellvibrio japonicus, genome annotation suggests that 17 genes are predicted to encode Carbohydrate-Active enZymes (CAZymes) with roles in cellulose degradation, however previous work suggested that only a subset of these genes is essential. Building upon that work, here we identify the required and minimally sufficient set of enzymes for complete degradation of cellulose using a combination of transcriptomics, gene deletion analysis, heterologous expression studies, and metabolite analysis. We identified six CAZyme-encoding required for cellulose deconstruction in C. japonicus, which are cel3B, cel5B, cel6A, lpmo10B, cbp2D, and cbp2E. These genes encode for a β-glucosidase, an endoglucanase, a cellbiohydrolase, a lytic polysaccharide mono-oxygenase, and two carbohydrate-binding proteins, respectively. These CAZyme-encoding genes are essential for growth using insoluble cellulose by C. japonicus, and sufficient using soluble cellulose when heterologously expressed in Escherichia coli. Moreover, during C. japonicus grow using insoluble cellulose we detected no cellodextrins in the medium, which suggests that cello-oligosaccharide uptake is highly efficient. RNAseq analysis corroborates these results, as we observed several genes significantly up-regulated during growth on cellulose that encode TonB-dependent and ABC transporters. Our revised model of cellulose utilization by C. japonicus suggests a greater importance for the Cbp2D and Cbp2E proteins than previously thought and that rapid cellodextrin update by C. japonicus is a mechanism to maximize the energetic return on investment for the production and secretion of CAZymes.
Project description:Brown rot fungi have great potential in biorefinery wood conversion systems, because they are the primary wood decomposers in coniferous forests and have an efficient lignocellulose degrading system. Their initial wood degradation mechanism is thought to consist of an oxidative radical-based system that acts sequentially with an enzymatic saccharification system, but the complete molecular mechanism of this system has not yet been elucidated. Some studies have shown that wood degradation mechanisms of brown rot fungi have diversity in their substrate selectivity. Gloeophyllum trabeum, one of the most studied brown rot species, has broad substrate selectivity and even can degrade some grasses. However, the basis for this broad substrate specificity is poorly understood. In this study, we performed RNA-seq analyses on G. trabeum grown on media containing glucose, cellulose, or Japanese cedar (Cryptomeria japonica) as the sole carbon source. Beyond the gene expression on glucose, 1129 genes were upregulated on cellulose and 1516 genes were upregulated on cedar. Carbohydrate Active enZyme (CAZyme) genes upregulated on cellulose and cedar media by G. trabeum included GH12, GH131, CE1, AA3_1, AA3_2, AA3_4 and AA9, which is a newly reported expression pattern for brown rot fungi. The upregulation of both terpene synthase and cytochrome P450 genes on cedar media suggests the potential importance of these genes in the production of secondary metabolites associated with the chelator-mediated Fenton reaction. These results provide new insights into the inherent wood degradation mechanism of G. trabeum and the diversity of brown rot mechanisms.
Project description:Various saprotrophic microorganisms, especially filamentous fungi, can efficiently degrade lignocellulose that is one of the most abundant natural material on earth. It consists of complex carbohydrates and aromatic polymers found in plant cell wall and thus in plant debris. Aspergillus fumigatus Z5 was isolated from compost heaps and showed highly efficient plant biomass-degradation capability.Genome analysis revealed an impressive array of genes encoding cellulases, hemicellulases, and pectinases involved in lignocellulosic biomass degradation. We sequenced the transcriptomes of Aspergillus fumigatus Z5 induced by sucrose, xylan, cellulose and rice straw, respectively. There were 444, 1711 and 1386 significantly differently (q-value ⤠0.0001 and |log2 of the ratio of the RPM values| ⥠2) expressed genes in xylan, cellulose and rice straw,respectively, relative to sucrose control. After incubation at 45 â, 145rpm for 20 hours with sucrose as the carbon source, mycelia were induced for 16 hours using xylan, cellulose and rice straw, respectively. Transcriptome induced by sucrose was used as the control when comparing the differences between other three transcriptomes (induced by xylan, cellulose and rice straw, respectively).
Project description:Various saprotrophic microorganisms, especially filamentous fungi, can efficiently degrade lignocellulose that is one of the most abundant natural material on earth. It consists of complex carbohydrates and aromatic polymers found in plant cell wall and thus in plant debris. Aspergillus fumigatus Z5 was isolated from compost heaps and showed highly efficient plant biomass-degradation capability.Genome analysis revealed an impressive array of genes encoding cellulases, hemicellulases, and pectinases involved in lignocellulosic biomass degradation. We sequenced the transcriptomes of Aspergillus fumigatus Z5 induced by sucrose, xylan, cellulose and rice straw, respectively. There were 444, 1711 and 1386 significantly differently (q-value ≤ 0.0001 and |log2 of the ratio of the RPM values| ≥ 2) expressed genes in xylan, cellulose and rice straw,respectively, relative to sucrose control.