Transcriptome and secretome analysis of Aspergillus fumigatus in the presence of sugarcane bagasse

Autor(es)

de Gouvea, Paula Fagundes ^[1] ; Bernardi, Aline Vianna ^[1] ; Gerolamo, Luis Eduardo ^[1] ; Santos, Emerson de Souza ^[2] ; Riano-Pachon, Diego Mauricio ^{[3, 4]} ; Uyemura, Sergio Akira ^[2] ; Dinamarco, Taisa Magnani ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Philosophy Sci & Literature Ribeirao Preto, Chem Dept, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Clin Toxicol & Bromatol Anal, Ribeirao Preto, SP - Brazil

^[3] Brazilian Bioethanol Sci & Technol Lab, Campinas, SP - Brazil

^[4] Univ Sao Paulo, Inst Chem, Dept Biochem, Lab Regulatory Syst Biol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BMC Genomics; v. 19, APR 3 2018.
• Citações Web of Science: 10

Resumo

Background: Sugarcane bagasse has been proposed as a lignocellulosic residue for second-generation ethanol (2G) produced by breaking down biomass into fermentable sugars. The enzymatic cocktails for biomass degradation are mostly produced by fungi, but low cost and high efficiency can consolidate 2G technologies. A. fumigatus plays an important role in plant biomass degradation capabilities and recycling. To gain more insight into the divergence in gene expression during steam-exploded bagasse (SEB) breakdown, this study profiled the transcriptome of A. fumigatus by RNA sequencing to compare transcriptional profiles of A. fumigatus grown on media containing SEB or fructose as the sole carbon source. Secretome analysis was also performed using SDS-PAGE and LC-MS/MS. Results: The maximum activities of cellulases (0.032 U mL-1), endo-1,4-beta-xylanase (10.82 U mL-1) and endo-1,3-beta glucanases (0.77 U mL-1) showed that functional CAZymes (carbohydrate-active enzymes) were secreted in the SEB culture conditions. Correlations between transcriptome and secretome data identified several CAZymes in A. fumigatus. Particular attention was given to CAZymes related to lignocellulose degradation and sugar transporters. Genes encoding glycoside hydrolase classes commonly expressed during the breakdown of cellulose, such as GH-5, 6, 7, 43, 45, and hemicellulose, such as GH-2, 10, 11, 30, 43, were found to be highly expressed in SEB conditions. Lytic polysaccharide monooxygenases (LPMO) classified as auxiliary activity families AA9 (GH61), CE (1, 4, 8, 15, 16), PL (1, 3, 4, 20) and GT (1, 2, 4, 8, 20, 35, 48) were also differentially expressed in this condition. Similarly, the most important enzymes related to biomass degradation, including endoxylanases, xyloglucanases, beta-xylosidases, LPMOs, alpha-arabinofuranosidases, cellobiohydrolases, endoglucanases and beta-glucosidases, were also identified in the secretome. Conclusions: This is the first report of a transcriptome and secretome experiment of Aspergillus fumigatus in the degradation of pretreated sugarcane bagasse. The results suggest that this strain employs important strategies for this complex degradation process. It was possible to identify a set of genes and proteins that might be applied in several biotechnology fields. This knowledge can be exploited for the improvement of 2G ethanol production by the rational design of enzymatic cocktails. (AU)

• Processo FAPESP: 14/10466-0 - Análise transcricional do fungo Aspergillus fumigatus quando crescido em bagaço de cana-de-açúcar
• Beneficiário: Taisa Magnani Dinamarco
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular