First Insights Into Bacterial Gastrointestinal Tract Communities of the Eurasian Beaver (Castor fiber)

Abstract

The Eurasian or European beaver ( Castor fiber ) is the second-largest living rodent after the capybara. It is a semi-aquatic animal known for building dams and lodges. They strictly feed on lignocellulose-rich plants and correspondingly harbor cellulolytic microbial communities in their digestive tract. In this study, the bacterial community composition, diversity, and functional profile of different gut compartments ranging from stomach to colon have been explored. A total of 277 bacterial operational taxonomic units (OTUs) at species level were obtained from the gut systems of two males (juvenile and subadult) and one subadult female beaver. In general, cecum and colon are dominated by Firmicutes and Actinobacteria. High abundance of Bacteroidetes was observed only in male juvenile beaver cecum and colon, suggesting that the bacterial composition changes with age. Within the cecum and colon, members of known cellulase-producing bacterial taxa including the families Ruminococcaceae, Lachnospiraceae, and Clostridiaceae 1 were detected. The presence of putative genes encoding cellulolytic and carbohydrate-degrading enzymes indicated also the degradation of recalcitrant plant material in both gut compartments. The bacterial community in the gut systems of the Eurasian beaver differed from that of the North American beaver. Higher abundance of Actinobacteria and lower abundances of Bacteroidetes were recorded in the Eurasian beaver. Similar differences were obtained to bacterial communities of termites and herbivorous animals such as bovine. The data presented in this study provides the first insight into bacterial communities in the gut system of the Eurasian beaver.

Gut microbiome of the largest living rodent harbors unprecedented enzymatic systems to degrade plant polysaccharides

“…This variability would be an indicative of a potential feed specialization such as from wild animals dwelling in the Brazilian sugarcane belt, and/or microbial dynamics and adaptation to nutrient availability. A prevalence of Firmicutes, Bacteroidetes, and Proteobacteria was also observed in the gut microbiota of beaver, horse, rabbit, and koala 16 – 20 , indicating to be a common feature among hindgut herbivores. Comparative investigation of the gut microbiota of a large number of carnivores, omnivores, and herbivores, observed a lower microbiota biodiversity in cecum fermenters (such as capybara, beaver, and rabbit) compared to colon fermenters (such as horse, elephant, and tapir), despite their high plant fiber-based diets 21 .…”

Gut Microbiome of the Amazon Master of the Grasses Harbors Unprecedented Enzymatic Strategies for Plant Glycans Breakdown

“…A dominance of Firmicutes, Proteobacteria, Bacteroidetes and Tenericutes was observed in the hindgut microbiomes of other herbivores such as Castor ber, Castor canadensis, horse, rabbit and koala (16)(17)(18)(19)(20). Further, microbiota analysis of domesticated herbivores including hindgut fermenters, ruminants and monogastric animals revealed Firmicutes as the dominant phylum (53.11, 63.35 and 52.27% respectively), followed by Bacteroidetes (31.36, 20.95 and 26.95%, respectively).…”

Gut microbiome of capybara, the Amazon master of the grasses, harbors unprecedented enzymatic strategies for plant glycans breakdown

“…A prevalence of Firmicutes, Proteobacteria, Bacteroidetes and Tenericutes was observed in the gut microbiomes of other hindgut herbivores such as Castor ber, Castor canadensis, horse, rabbit, and koala [18][19][20][21][22]. Furthermore, microbiota analysis of domesticated herbivores including hindgut fermenters, ruminants and monogastric animals revealed Firmicutes as the most abundant phylum (53.11, 63.35 and 52.27%, respectively), followed by Bacteroidetes (31.36, 20.95 and 26.95%, respectively) [23].…”