Microbial Enrichments Contribute to Characterization Of Desert Tortoise Gut Microbiota

TL;DR

This study explores the gut microbiota of desert tortoises and identifies microbes that help break down plant material, which could have biotech applications.

Contribution

The study provides new insights into the gut microbiota of desert tortoises and identifies key microbes involved in lignocellulose degradation.

Findings

Cultivated microbial communities were rich in Firmicutes and Bacteroidota, known for biomass deconstruction.

Lachnospiraceae and Enterococcus thrived in lignocellulose enrichments and produced short-chain fatty acids.

The study shows potential for biotechnological use of these microbes to convert plant material into useful metabolites.

Abstract

Desert tortoises play ecologically significant roles, including plant seed dispersal and mineral cycling, and yet little is known about microbial members that are critical to their gut and overall health. Tortoises consume recalcitrant plant material, which their gut microbiota degrades and converts into usable metabolites and nutrients for the tortoise. Findings from tortoise gut microbiomes may translate well into biotechnological applications as these microbes have evolved to efficiently degrade recalcitrant substrates and generate useful products. In this study, we cultivated microbial communities from desert tortoise fecal samples following a targeted anaerobic enrichment for microbes involved in deconstruction and utilization of plant biomass. We employed 16S rRNA amplicon sequencing to compare cultivated communities to initial fecal source material and found high abundances of Firmicutes and Bacteroidota typically associated with biomass deconstruction in all cultivated samples. Significantly decreased microbial diversity was observed in the cultivated microbial communities, yet several key taxa thrived in lignocellulose enrichments, including Lachnospiraceae and Enterococcus. Additionally, cultivated communities produced short-chain fatty acids under anaerobic conditions, and their growth and metabolic output provide evidence of their viability in the initial fecal communities. Overall, this study adds to the limited understanding of reptilian herbivore microbiota, and offers a path towards biotechnological translation based on the ability of the cultivated communities to convert lignocellulose directly to acetate, propionate, and butyrate.

The online version contains supplementary material available at 10.1007/s00248-025-02557-6.

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