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| Author(s): |
Renato Augusto Corrêa dos Santos
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2018-02-08 |
| Examining board members: |
Gustavo Henrique Goldman;
Gabriela Felix Persinoti;
Rafael Silva Rocha
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| Advisor: | Diego Mauricio Riaño Pachón; Gustavo Henrique Goldman |
| Abstract | |
Fungi in phylum Basidiomycota comprise the most relevant in decomposition of organic matter in our planet, and members of the Agaricomycotina sub-phylum are the main involved in deconstruction of lignocellulosic biomass. The family Ustilaginaceae belongs to sub-phylum Ustilaginomycotina, a sister clade of Agaricomycotina, and includes important grass phytopathogens and non-pathogenic yeasts, both have been highlighted because of their biotechnological potential, including production of enzymes for deconstruction of plant cell wall polymers. Xylan is the main component of the hemicellulosic portion of plant cell wall and the comprehension of its degradation by fungi, as well as the transport of its monomer, xylose, and its internal metabolism are essential for industrial application and genetic improvement of these organisms, including production of Second Generation Bioethanol. The xylanolytic yeast Kalmanozyma brasiliensis GHG001 (previously Pseudozyma brasiliensis) is a member of Ustilaginaceae isolated from the gut of a Chrysomelidae larvae that parasitized sugarcane, during a screening of yeasts able to ferment xylose, and was outstanding in overproduction of an endoxylanase of family GH11. Omics approaches are valuable for exploitation of the potential of lignocellulosic biomass deconstruction. Previous works have been carried out that included comparative genomics of several fungal groups within ascomycetes and basidiomycetes with focus on lignocellulose degradation and transcriptomics employing RNA-seq in basidiomycetes has already been carried out for understanding of lignocellulose degradation, but limited to Agaricomycotina. Despite its biotechnological importance and availability of genome sequences for several of its members, the family Ustilaginaceae remains underexplored. In this work, omics approaches have been applied to exploit the biotechnological potential of this fungal family with focus on xylan degradation and xylose metabolism. First, a transcriptomic analysis with RNA-seq was employed to improve our comprehension of xylan and xylose metabolism in K. brasiliensis GHG001, including the expression of genes coding for xylan degrading enzymes, putative xylose transporters, and possible transcriptional regulatory proteins. RNA-seq analysis was also used to improve the genome structural annotation of the yeast. Next, a comparative genomics approach was used to exploit other members of the fungal family with sequenced genomes, including three novel ustilaginaceous yeasts, possibly new species, isolated from flowers of Heliconia psittacorum, Moesziomyces spp. F16C1 and F8B2, and Pseudozyma sp. F5C1 pro tempore, potentially novel species. RNA-seq analyses improved the structural annotation of the K. brasiliensis GHG001 genome and allowed a better understanding of the pentose metabolism and regulation of gene expression. Phylogenetic analyses of the family Ustilaginaceae contributed to its Systematics, allowing the placement of sequenced yeasts and providing an accurate phylogeny for the comparative genomic analysis. Lastly, the prevalence of CAZYmes and the evolution (expansions and contractions) of CAZYme and TAP families highlighted important aspects for raising hypotheses about the fungal family (AU) | |
| FAPESP's process: | 14/15799-7 - Genomic analysis of the xylanolytic yeast Pseudozyma brasiliensis |
| Grantee: | Renato Augusto Corrêa dos Santos |
| Support Opportunities: | Scholarships in Brazil - Master |