North American Beaver (Castor canadensis) gut mycobiome

Abstract

The North American Beaver (Castor canadensis) is a semi-aquatic, hindgut-fermenting rodent that follows a tree bark-based diet and shows long feed retention time (14-40 hours). Their enlarged cecum harbors a complex microbial community that plays a key role in lignocellulose degradation. While some studies have investigated its gut microbiome, most focused on bacteria and archaea with little attention to the fungal community. Since anaerobic gut fungi (AGF) are known lignocellulose degraders in other herbivores, we hypothesize that beavers host AGF and furthermore possess a unique fungal community due to their lignocellulose-rich diet. To test this hypothesis, cecal samples from 32 wild beavers were collected by trappers throughout the state of Utah. Amplicon sequencing targeting the D2 region of the LSU rRNA gene of the general fungal community has been performed. Preliminary results showed that Neocallimastigomycota constituted an integral component of the beaver’s gut (~23% of the total fungal community). Within this AGF community, genera encountered included Orpinomyces, Liebetanzomyces, and a novel genus in the Joblinomyces clade. Other than Neocallimastigomycota, the beaver gut harbored novel fungal lineages closely related to the Neocallimastigomycota and Chytridiomycota (~63% of the total fungal community). Comparative analysis of all 32 samples will elucidate community differences based on sex, age, and weight. In addition, enrichment and isolation efforts are underway. This study provides the first report of AGF in beavers and aims to comprehensively characterize the fungal community associated with North American beavers.Microbiology and Molecular Genetic