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| Author(s): |
Déborah Aires Almeida
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: | 2019-08-21 |
| Examining board members: |
Anete Pereira de Souza;
Marcelo Falsarella Carazzolle;
Adriano Rodrigues Azzoni
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| Advisor: | Anete Pereira de Souza |
| Abstract | |
Brazil is the leading producer of sugarcane in the world that after being processed it generates large quantities of by-products, principally sugarcane bagasse, which can be converted into second-generation ethanol. However, one of the main challenges is to obtain efficient enzymes for the hydrolysis of plant biomass. Saprotrophic microorganisms play an important role in producing plant cell wall-degrading enzymes being an attractive target for applications in industrial biotechnological processes. Thus, species in the filamentous ascomycete genus Trichoderma have been widely exploited. T. harzianum is a commonly employed species as a biocontrol agent but studies have also shown their potential in producing a set of enzymes capable of promoting the saccharification of plant biomass efficiently and are, therefore, being investigated as a valuable source of hydrolytic enzymes for industrial usage. This work aimed to identify and analyze, through RNA sequencing (RNA-Seq) and exoproteome, the set of genes related to the hydrolysis of plant biomass by T. harzianum CBMAI-0179 using crystalline cellulose and glucose as a carbon source. Enzymes related to carbohydrate degradation are classified according to the Carbohydrate-active enzymes (CAZy) database. We identified in this strain, 219 differentially expressed genes under cellulose condition in relation to glucose and among these, 35 CAZymes were identified including 2 AAs (auxiliary activities), 21 GHs (glycoside hydrolases), 1 GT (glycosyltransferase), 2 CEs (carbohydrate esterases) and 9 CBMs (carbohydrate-binding modules). CAZyme families were classified, quantified and the main families of cellulases and hemicellulases were analyzed based on the expression level of the genes. We found in the transcriptomic analysis, 9 differentially expressed CAZymes (GH1, GH3, GH5, GH6, GH7, GH45 and AA9) related to cellulose degradation and 1 differentially expressed CAZyme (GH10) related to hemicellulose degradation, in which the data was compared with other species of the same genus (T. harzianum IOC-3844 and T. atroviride CBMAI-0020). In the exoproteome analysis, a total of 32 secreted proteins were detected in the cellulose aqueous extract such as beta-glucosidases, endoglucanases, cellobiohydrolase, lytic polysaccharide monooxygenase (LPMO), endo-1,4-beta-xylanases and beta-mannanase. These data were correlated with the transcriptome analysis in order to observe the expression level of the genes that encoded the secreted proteins. Thus, co-expression networks were constructed from correlation data of the expression level of the genes where it was possible to explore the relationship among the genes with secreted proteins that act synergistically for cellulose degradation. In addition, through the functional annotation, we could identify some important genes related to transcription factors (TFs), major facilitator superfamily (MFS) transporters and ATP-binding cassette (ABC) transporters. Therefore, these results demonstrate the potential of T. harzianum for efficient hydrolytic enzymes bioprospection for application in enzymatic cocktails for second-generation ethanol production (AU) | |
| FAPESP's process: | 17/17782-2 - Transcriptional analysis of Trichoderma harzianum CBMAI-0179 during cellulose and glucose degradation |
| Grantee: | Déborah Aires Almeida |
| Support Opportunities: | Scholarships in Brazil - Master |