Cyanobacteria morphotypes with simple morphology, mainly thin filamentous homocytous strains, comprise a taxonomically complex group and represent a challenge in systematic studies. However, the polyphasic approach applied nowadays to investigate the cyanobacterial diversity has emerged as a powerful tool to undercover cryptic taxa and to set up a more natural classification system. Yet, studies exploring the cultured diversity of cyanobacteria from extreme tropical environments have paved the way to the discovery of new cyanobacteria taxa, enabling the description of Pantanalinema, Alkalinema, and Cephalothrix as novel genera from saline–alkaline lakes in Pantanal wetlands (Brazil). The present study investigated a set of cyanobacterial strains resembling Leptolyngbya morphotypes by means of its morphology, 16S ribosomal RNA (16S rRNA) phylogeny, and ITS secondary structures. Based on the shape and structure of their trichomes, the low levels of 16S rRNA identity coupled with the distinct phylogenetic position with regard to well establish genera, and their divergent ecological feature, these strains must be accommodated into a novel genus, named as Monilinema gen. nov., described under the provisions of the International Code of Nomenclature for algae, fungi, and plants. Accordingly, based on the singularity of the D1–D1′ and V3 helixes, these strains should be considered as a single species, Monilinema alkalinum.

中文翻译：

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Monilinema gen。nov。，来自巴西潘塔纳尔湿地的盐碱湖的同胞属（蓝细菌，钩端草科）

具有简单形态的蓝细菌形态型，主要是稀薄的丝状同型细胞株，包括一个分类学上复杂的基团，代表了系统研究中的一个挑战。然而，如今用于研究蓝细菌多样性的多相方法已成为隐藏隐蔽分类群和建立更自然分类系统的有力工具。然而，研究探索蓝藻从极端热带环境中的培养的多样性已经铺平了道路新蓝藻类群的发现，使的描述Pantanalinema，Alkalinema和Cephalothrix如从潘塔纳尔沼泽地（巴西）盐碱湖泊新颖属。本研究调查了一组类似的蓝细菌菌株通过形态学，16S核糖体RNA（16S rRNA）系统发育和ITS二级结构来鉴定Lyptolyngbya的形态。基于它们的毛状体的形状和结构，低水平的16S rRNA身份以及相对良好建立属的独特系统发育位置以及其不同的生态特征，必须将这些菌株容纳到一个名为Monilinema gen的新属中。。nov。，根据《藻类，真菌和植物国际命名法》的规定进行了描述。因此，基于D1-D1'和V3螺旋的奇异性，应将这些菌株视为一个单一种，即碱菌。