# Comparative Enzymology and Biomass Hydrolysis Reveal Industrial Biorefining Potential of Aspergillus fumigatus Strain VP2T

## TL;DR

A thermophilic fungus, Aspergillus fumigatus VP2T, shows strong potential for industrial biomass conversion due to its high enzyme activity and efficient lignocellulose breakdown.

## Contribution

Discovery of a native thermophilic fungal strain with high lignocellulolytic enzyme activity and superior biomass hydrolysis efficiency.

## Key findings

- A. fumigatus VP2T produces 131 U/mL cellobiose dehydrogenase and 33 U/mL endoglucanase, exceeding many fungal strains.
- The strain achieves 1.89-fold higher saccharification efficiency on rice straw compared to Cellic® CTec2.
- Genomic analysis reveals over 300 carbohydrate-active enzymes, including oxidative enzymes that enhance biomass degradation.

## Abstract

We report on the isolation and comprehensive genomic and biochemical characterization of Aspergillus fumigatus VP2T, a thermophilic filamentous fungus recovered from Himalayan Forest soil with exceptional lignocellulolytic capacity. Whole-genome sequencing revealed a 32.1 Mb genome encoding 12,675 predicted genes, including an extensive repertoire of >300 carbohydrate-active enzymes (CAZymes). Notably, the genome harbors multiple auxiliary activity enzymes, including AA9-family lytic polysaccharide monooxygenases and several cellobiose dehydrogenases (CDHs), supporting oxidative–hydrolytic synergism during biomass degradation. Submerged fermentation using a cellulose–wheat bran–rice straw substrate induced high enzyme titers, including 33 U/mL endoglucanase and 131 U/mL CDH, exceeding activities commonly reported for both native and engineered fungal strains. Although exoglucanase (0.02 U/mL) and xylanase (14.22 U/mL) activities were comparatively modest, the strain VP2T demonstrated superior hydrolysis of untreated rice straw, achieving a 1.89-fold increase in saccharification efficiency relative to the commercial enzyme cocktail Cellic® CTec2. Scanning electron microscopy confirmed extensive disruption of lignocellulosic architecture, consistent with enhanced enzyme accessibility and oxidative fiber loosening. Collectively, genomic evidence and functional assays identify A. fumigatus VP2T as a redox-optimized, moderately thermophilic biocatalyst suited for low-pH lignocellulose conversion. This study highlights the value of exploring thermophilic fungal biodiversity to discover native strains with inherent oxidative capacity, offering promising alternatives to pretreatment-intensive biorefinery processes and informing the rational development of tailored enzyme systems.