title: Thermotolerant and mesophylic fungi from sugarcane bagasse and their prospection for biomass-degrading enzyme production.
abstract: Nineteen fungi and seven yeast strains were isolated from sugarcane bagasse piles from an alcohol plant located at Brazilian Cerrado and identified up to species level on the basis of the gene sequencing of 5.8S-ITS and 26S ribosomal DNA regions. Four species were identified: Kluyveromyces marxianus, Aspergillus niger, Aspergillus sydowii and Aspergillus fumigatus, and the isolates were screened for the production of key enzymes in the saccharification of lignocellulosic material. Among them, three strains were selected as good producers of hemicellulolitic enzymes: A. niger (SBCM3), A. sydowii (SBCM7) and A. fumigatus (SBC4). The best β-xylosidase producer was A. niger SBCM3 strain. This crude enzyme presented optimal activity at pH 3.5 and 55 °C (141 U/g). For β-glucosidase and xylanase the best producer was A. fumigatus SBC4 strain, whose enzymes presented maximum activity at 60 °C and pH 3.5 (54 U/g) and 4.0 (573 U/g), respectively. All these crude enzymes presented stability around pH 3.0-8.0 and up to 60 °C, which can be very useful in industrial processes that work at high temperatures and low pHs. These enzymes also exhibited moderate tolerance to ethanol and the sugars glucose and xylose. These similar characteristics among these fungal crude enzymes suggest that they can be used synergistically in cocktails in future studies of biomass conversion with potential application in several biotechnological sectors.
authors.affiliation: Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil .
authors.forename: Bruna Silveira Lamanes dos
authors.initials: BS
authors.lastname: Santos
authors.affiliation: Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil .
authors.forename: Arthur Filipe Sousa
authors.initials: AF
authors.lastname: Gomes
authors.affiliation: Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil .
authors.forename: Emanuele Giuliane
authors.initials: EG
authors.lastname: Franciscon
authors.affiliation: Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil .
authors.forename: Jean Maikon de
authors.initials: JM
authors.lastname: Oliveira
authors.affiliation: Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil .
authors.forename: Milla Alves
authors.initials: MA
authors.lastname: Baffi
mesh_terms: D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000302:isolation & purification / Q000378:metabolism; D001234:Aspergillus niger / Q000201:enzymology* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D018533:Biomass; D001938:Brazil; D002482:Cellulose / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics; D021901:DNA, Intergenic / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D005285:Fermentation; D007716:Kluyveromyces / Q000201:enzymology* / Q000302:isolation & purification / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D058889:Molecular Typing; D016533:Mycological Typing Techniques; D012335:RNA, Ribosomal / Q000235:genetics; D031786:Saccharum / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D014995:Xylosidases / Q000378:metabolism*; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D021901:DNA, Intergenic; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; C027433:bagasse; D014995:Xylosidases; D001617:beta-Glucosidase; D043364:Endo-1,4-beta Xylanases
keywords: Aspergillus; sugarcane bagasse; xylanase; β-glucosidase; β-xylosidase