Thermotolerant and mesophylic fungi from sugarcane bagasse and their prospection for biomass-degrading enzyme production.
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.
['Santos|Bruna Silveira Lamanes dos|BS|', 'Gomes|Arthur Filipe Sousa|AF|', 'Franciscon|Emanuele Giuliane|EG|', 'Oliveira|Jean Maikon de|JM|', 'Baffi|Milla Alves|MA|']
D001232:Aspergillus fumigatus D001234:Aspergillus niger D001483:Base Sequence D018533:Biomass D001938:Brazil D002482:Cellulose D004271:DNA, Fungal D021901:DNA, Intergenic D043364:Endo-1,4-beta Xylanases D005285:Fermentation D007716:Kluyveromyces D008031:Lignin D058889:Molecular Typing D016533:Mycological Typing Techniques D012335:RNA, Ribosomal D031786:Saccharum D017422:Sequence Analysis, DNA D014995:Xylosidases D001617:beta-Glucosidase
sugarcane bagasse Aspergillus β-xylosidase β-glucosidase xylanase