Blair Elaina M, Margalith Noa J, O'Malley Michelle A
Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA.
Department of Chemical & Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.
Microb Ecol. 2025 Jun 17;88(1):66. doi: 10.1007/s00248-025-02557-6.
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.
沙漠陆龟发挥着重要的生态作用，包括植物种子传播和矿物质循环，但对于对其肠道及整体健康至关重要的微生物成员，我们却知之甚少。陆龟食用难降解的植物材料，其肠道微生物群体会将这些材料降解并转化为陆龟可用的代谢物和营养物质。陆龟肠道微生物组的研究结果可能很好地转化为生物技术应用，因为这些微生物已经进化到能够有效降解难降解的底物并产生有用的产品。在本研究中，我们对沙漠陆龟粪便样本中的微生物群落进行了培养，针对参与植物生物质解构和利用的微生物进行了有针对性的厌氧富集。我们采用16S rRNA扩增子测序将培养的群落与初始粪便源材料进行比较，发现在所有培养样本中，通常与生物质解构相关的厚壁菌门和拟杆菌门丰度很高。在培养的微生物群落中观察到微生物多样性显著降低，但几个关键分类群在木质纤维素富集中茁壮成长，包括毛螺菌科和肠球菌。此外，培养的群落在厌氧条件下产生短链脂肪酸，它们的生长和代谢产物证明了它们在初始粪便群落中的生存能力。总体而言，本研究增加了我们对爬行动物食草动物微生物群的有限了解，并基于培养群落将木质纤维素直接转化为乙酸盐、丙酸盐和丁酸盐的能力，为生物技术转化提供了一条途径。
