The anaerobic gut fungi (AGF, phylum Neocallimastigomycota) reside in the alimentary tracts of herbivores. Multiple novel, yet-uncultured AGF taxa have recently been identified in culture-independent diversity surveys. Here, we report on the isolation and characterization of the first representative of the RH5 lineage from fecal samples of a wild blackbuck (Indian Antelope) from Sutton County, Texas, USA. The isolates displayed medium sized (2-4 mm) compact circular colonies on agar roll tubes and thin loose biofilm-like growth in liquid medium. Microscopic examination revealed monoflagellated zoospores and polycentric thalli with highly branched nucleated filamentous rhizomycelium, a growth pattern encountered in a minority of described AGF genera so far. The obtained isolates are characterized by formation of spherical vesicles at the hyphal tips from which multiple sporangia formed either directly on the spherical vesicles or at the end of sporangiophores. Phylogenetic analysis using the D1/D2 regions of the large ribosomal subunit (D/D2 LSU) and the ribosomal internal transcribed spacer 1 (ITS1) revealed sequence similarities of 93.5%, and 81.3%, respectively, to the closest cultured relatives (Orpinomyces joyonii strain D3A (D1/D2 LSU), and Joblinomyces apicalis strain GFH681 (ITS1). Substrate utilization experiments using the type strain (BB-3) demonstrated growth capabilities on a wide range of mono-, oligo-, and polysaccharides, including glucose, xylose, mannose, fructose, cellobiose, sucrose, maltose, trehalose, lactose, cellulose, xylan, starch, and raffinose. We propose accommodating these novel isolates in a new genus and species, for which the name Paucimyces polynucleatus is proposed. The type species is strain BB-3.

中文翻译：

---

Paucimyces多核基因。十一月 nov。，一种来自野生黑鹿羚羊粪便的新型厌氧菌多中心属

厌氧性肠道真菌（AGF，新Callimastigomycota门）位于食草动物的消化道中。最近在与文化无关的多样性调查中发现了多个新颖但尚未培养的AGF类群。在这里，我们报道了从美国德克萨斯州萨顿县的野生黑buck（印度羚羊）的粪便样本中分离并鉴定了RH5谱系的第一个代表。分离物在琼脂卷管上显示中等大小（2-4毫米）的紧凑圆形菌落，并在液体培养基中生长出薄薄的生物膜状生长物。显微镜检查显示单鞭毛的游动孢子和多中心的塔利与高度分支的有核丝状根状菌丝体，到目前为止，在所述的少数AGF属中都遇到了这种生长方式。所获得的分离物的特征在于在菌丝尖端形成球形囊泡，由此直接在球形囊泡上或在孢子囊的末端形成多个孢子囊。使用大核糖体亚基（D / D2 LSU）的D1 / D2区和核糖体内部转录间隔区1（ITS1）进行的系统进化分析显示，与最接近的培养亲戚（Orpinomyces joyonii）的序列相似性分别为93.5％和81.3％。 D3A（D1 / D2 LSU）菌株和阿比伯氏假丝酵母GFH681（ITS1）。使用菌株（BB-3）进行的底物利用实验证明了其在各种单糖，寡糖和多糖（包括葡萄糖）上的生长能力，木糖，甘露糖，果糖，纤维二糖，蔗糖，麦芽糖，海藻糖，乳糖，纤维素，木聚糖，淀粉和棉子糖。我们建议将这些新的分离物容纳在一个新的属和种中，为此提出了名字为Paucimyces polynucleatus的名称。类型种类是菌株BB-3。