Paucimyces polynucleatus gen. nov, sp. nov., a novel polycentric genus of anaerobic gut fungi from the faeces of a wild blackbuck antelope
Paucimyces polynucleatus gen. nov, sp. nov., a novel polycentric genus of anaerobic gut fungi from the faeces of a wild blackbuck antelope
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DOI：
10.1099/ijsem.0.004832
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发表时间：
2021-01-01
影响因子：
2.8
通讯作者：
Elshahed, Mostafa S.
中科院分区：
文献类型：
--
作者：
Hanafy, Radwa A.;Youssef, Noha H.;Elshahed, Mostafa S.
厌氧肠道真菌（AGF；新菌门）存在于食草动物的消化道中。最近，在与培养无关的多样性调查中发现了多个新的、尚未培养的AGF分类群。本文报道了从美国德克萨斯州萨顿县野生黑羚（印第安羚羊，Antilope cervicapra）的粪便样本中分离和鉴定的第一个RH5谱系代表。分离株在琼脂卷管上显示中等大小（2-4 mm）紧凑的圆形菌落，在液体培养基中生长薄而松散的生物膜样。显微镜检查显示单鞭毛游动孢子和多中心菌体具有高度分枝的有核丝状根菌，这是迄今为止在少数已描述的AGF属中遇到的生长模式。所获得的分离株的特征是在菌丝尖端形成球形囊泡，多个孢子囊直接在球形囊泡上或在孢子囊的末端形成。利用大核糖体亚基（D1/D2 LSU）的D1/D2区域和核糖体内部转录间隔区1 （ITS1）进行系统发育分析，结果表明，该菌株与最近的培养亲缘菌(Orpinomyces joyonii菌株D3A （D1/D2 LSU）和顶端约布omyces apicalis菌株GFH681 （ITS1）的序列相似性分别为93.5%和81.3%。使用类型菌株（BB-3(T)）的底物利用实验证明了对多种单、低聚和多糖的生长能力，包括葡萄糖、木糖、甘露糖、果糖、纤维素二糖、蔗糖、麦芽糖、海藻糖、乳糖、纤维素、木聚糖、淀粉和棉子糖。我们建议将这些新分离物纳入一个新的属和种，并将其命名为Paucimyces polynucleatus gen. nov., sp. nov.。
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 faecal samples of a wild blackbuck (Indian Antelope, Antilope cervicapra) 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 (D1/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(T)) 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 gen. nov., sp. nov. is proposed.