High cellulolytic activities in filamentous fungi isolated from an extreme oligotrophic subterranean environment (Catão cave) in Brazil

• Main Authors: CAIO C.P. DE PAULA, QUIMI V. MONTOYA, LUCAS A. MEIRELLES, CRISTIANE S. FARINAS, ANDRÉ RODRIGUES, MIRNA H.R. SELEGHIM
• Format: Article
• Language: English
• Published: Academia Brasileira de Ciências
• Series: Anais da Academia Brasileira de Ciências
• Subjects: cellulases; fungu’s cave; solid state fermentation; submerged fermentation; subterranean environment
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000500601&lng=en&tlng=en

Abstract Abstract: Isolation and screening of new fungal strains from extreme and understudied environments, such as caves, is a promising approach to find higher yields enzyme producers. Cellulolytic fungal strains isolated from a Brazilian cave were evaluated for their enzymatic production after submerged (SmF) and solid-state fermentation (SSF). After SmF, three strains were selected for their high enzymatic activities: Aspergillus ustus for endoglucanase (4.76 U/mg), Talaromyces bruneus for β-glucosidase (11.71 U/mg) and Aspergillus sp. (CBMAI 1926) for total cellulase (1.70 U/mg). After SSF, these strains, showed better yields compared to the reference strain Aspergillus niger 3T5B8. Aspergillus sp. (CBMAI 1926) stood out as a new species that expressed activity of total cellulases (0.10 U/mg) and low protein concentration (0.44 mg/mL). In conclusion, these isolated strains have a more efficient and promising cellulolytic enzyme complex that can be used in fermentation and saccharification processes with a lower protein concentration and a higher enzymatic activity than the reference strain. Therefore, beside the new genetic material characterized, our study highlights the benefits of cave extreme environments exploitation to find new potentially valuable strains.