a Department of Microbiology and Molecular Genetics , Oklahoma State University , Stillwater , Oklahoma 74074.
Mycologia. 2018 May-Jun;110(3):513-525. doi: 10.1080/00275514.2018.1466610. Epub 2018 Jul 3.
Anaerobic gut fungi are common inhabitants of the alimentary tracts of herbivorous animals. Nine different Neocallimastigomycota genera have been described so far. However, culture-independent diversity surveys suggest the presence of numerous, yet-uncultured Neocallimastigomycota genera. Here, we report on the isolation and characterization of the first cultured representatives of Neocallimastigomycota clade AL6, originally identified in culture-independent surveys of fecal samples from captive wild animals. Six strains were isolated from rumen and fecal samples of a wild Barbary sheep (Ammotragus lervia) and a wild fallow deer (Dama dama) in Texas, USA. The isolates displayed medium-sized (3-7 mm), circular, beige colonies with filamentous edges and a dark center on agar roll tubes. Microscopic analysis revealed monocentric thalli with both endogenous and exogenous sporangial development patterns. Zoospores were spherical, with a diameter of 9.6 ± 1.9 μm, and polyflagellated, with 7-16 flagella. Phylogenetic analysis based on nuc rDNA ITS1 region and D1-D2 domains of nuc 28S rDNA revealed that the isolated strains formed a single monophyletic and bootstrap-supported clade distinct from all currently described Neocallimastigomycota genera. Substrate utilization experiments using the type strain (F3a) demonstrated robust and fast growth on sugars and plant biomass, as well as the capability to metabolize a wide range of mono-, oligo-, and polysaccharides, including galactose, arabinose, alginate, and pectin. On the basis of the morphological, physiological, and phylogenetic analyses, we propose to accommodate these isolates in a new genus, Feramyces (derived from the Latin word for "wild" to reflect their isolation and apparent distribution in undomesticated herbivores), and a new species, F. austinii. The type strain is Feramyces austinii F3a.
瘤胃厌氧真菌是食草动物消化道的常见栖息者。迄今为止，已经描述了 9 个不同的 Neocallimastigomycota 属。然而，非培养的多样性调查表明，存在许多尚未培养的 Neocallimastigomycota 属。在这里，我们报告了 Neocallimastigomycota 分支 AL6 的第一个培养代表的分离和特征，该分支最初是在对来自美国德克萨斯州圈养野生动物粪便样本的非培养调查中发现的。从一只野生巴巴里绵羊（Ammotragus lervia）和一只野生白尾鹿（Dama dama）的瘤胃和粪便样本中分离出了 6 株菌。分离株在琼脂滚管上显示出中等大小（3-7mm）、圆形、米色、丝状边缘、暗中心的菌落。显微镜分析显示单核体，具有内源性和外源性孢子囊发育模式。游动孢子为球形，直径 9.6±1.9μm，多鞭毛，有 7-16 根鞭毛。基于 nuc rDNA ITS1 区和 nuc 28S rDNA 的 D1-D2 区的系统发育分析表明，分离株形成了一个单系和自展支持的分支，与所有现有的 Neocallimastigomycota 属都不同。利用模式菌株（F3a）进行的底物利用实验表明，其能够快速而稳健地利用糖和植物生物质生长，并能够代谢广泛的单糖、寡糖和多糖，包括半乳糖、阿拉伯糖、藻酸盐和果胶。基于形态学、生理学和系统发育分析，我们建议将这些分离株归入一个新属， Feramyces（源自拉丁语的“野生”一词，以反映它们在未驯化的食草动物中的分离和分布），并归入一个新种， F. austinii。模式菌株是 Feramyces austinii F3a。
