Vinzelj Julia, Nash Kathryn, Jones Adrienne L, Young R Ty, Meili Casey H, Pratt Carrie J, Wang Yan, Elshahed Mostafa S, Youssef Noha H
Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74074, United States.
Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada.
ISME Commun. 2025 Aug 22;5(1):ycaf144. doi: 10.1093/ismeco/ycaf144. eCollection 2025 Jan.
Anaerobic gut fungi (AGF; ) are crucial for the degradation of plant biomass in herbivores. While extensively studied in mammals, information regarding their occurrence, diversity, and community structure in nonmammalian hosts remains sparse. Here, we report on the AGF community in fecal samples of 13 domesticated ostriches. The ostrich () is an herbivorous, flightless, hindgut-fermenting member of the class (birds). Illumina-based metabarcoding targeting the D2 region of the large ribosomal subunit (28S rRNA) revealed a uniform AGF community with low alpha diversity in the fecal samples. The community was mostly comprised of sequences potentially representing two novel species in the genus and a novel genus in the . Sequences affiliated with these novel taxa were absent or extremely rare in datasets derived from mammalian and tortoise samples, indicating a strong pattern of AGF-host association. One strain (strain Ost1) was successfully isolated. Transcriptomics-enabled molecular dating analysis suggested a divergence time of ≈ 30Mya, a time frame in line with current estimates for ostrich evolution. Comparative gene content analysis between strain Ost1 and other species from mammalian sources revealed a high degree of similarity. Our findings expand the range of AGF animal hosts to include members of the birds (class ), highlight a unique AGF community in the ostrich alimentary tract, and document the occurrence of a strong pattern of fungal-host association in ostriches, similar to previously observed patterns in AGF canonical mammalian hosts.
厌氧肠道真菌（AGF；）对于食草动物体内植物生物质的降解至关重要。虽然在哺乳动物中已得到广泛研究，但关于它们在非哺乳动物宿主中的存在、多样性和群落结构的信息仍然稀少。在此，我们报告了13只家养鸵鸟粪便样本中的AGF群落。鸵鸟（）是鸟类纲中一种食草、不会飞且后肠发酵的成员。基于Illumina的元条形码分析针对大核糖体亚基（28S rRNA）的D2区域，揭示了粪便样本中一个均匀的AGF群落，其α多样性较低。该群落主要由可能代表属中两个新物种和纲中一个新属的序列组成。在源自哺乳动物和乌龟样本的数据集中，与这些新分类群相关的序列不存在或极为罕见，这表明AGF与宿主之间存在强烈的关联模式。成功分离出一株菌株（菌株Ost1）。基于转录组学的分子年代分析表明分歧时间约为3000万年前，这一时间框架与目前对鸵鸟进化的估计一致。对菌株Ost1与来自哺乳动物来源的其他物种进行的比较基因含量分析显示出高度相似性。我们的研究结果将AGF动物宿主的范围扩大到包括鸟类纲成员，突出了鸵鸟消化道中独特的AGF群落，并记录了鸵鸟中真菌与宿主之间存在强烈关联模式的情况，类似于之前在AGF典型哺乳动物宿主中观察到的模式。
