Genome analysis and CAZy repertoire of a novel fungus Aspergillus sydowii C6d with lignocellulolytic ability isolated from camel rumen

Abstract

Background: Camels are known for their survival under harsh and nutrient-deficient climates. Camel rumen ecosystem presents a unique opportunity to study the ruminal microbes helping the camel in this task. The genus Aspergillus is the extensively studied filamentous fungus due to its ability to secret industrially important enzymes. The present study was aimed to isolate and characterize microbes with lignocellulolytic capacity from camel rumen.

Results: The fungal isolate Aspergillus sydowii C6d, isolated from camel rumen, was sequenced and analyzed for its CAZyme content responsible for lignocellulose degradation. The C6d isolate was evaluated for its capacity to produce cellulase, pectinase, xylanase, and amylase with their respective assays and further evaluated for their optimum pH. The genome sequencing and assembly resulted in 32.27 Mb of genome size with a GC % of 50.59. The CAZyme analysis revealed that the C6d produced 543 polysaccharide-degrading CAZymes amongst which, 148 CAZymes were potentially involved in lignocellulose degradation. The genomic comparison of the C6d with 30 commonly used lignocellulolytic fungi (white rot, brown rot, and soft rot fungus) showed the enrichment of cellulolytic and pectinolytic CAZymes in C6d genome as compared to others. The saccharification of lignocellulosic substrate wheat straw resulted in the release of 50.85% of reducing sugars.

Conclusions: The study provides important insights into the CAZymes responsible for lignocellulolytic ability in the novel fungus Aspergillus sydowii C6d isolated from camel rumen and presents a valuable source of CAZymes to be further evaluated for potential biotechnological applications.