The true-branching cyanobacterium Fischerella thermalis (also known as Mastigocladus laminosus) is widely distributed in hot springs around the world. Morphologically, it has been described as early as 1837. However, its taxonomic placement remains controversial. F. thermalis belongs to the same genus as mesophilic Fischerella species but forms a monophyletic clade of thermophilic Fischerella strains and sequences from hot springs. Their recent divergence from freshwater or soil true-branching species and the ongoing process of specialization inside the thermal gradient make them an interesting evolutionary model to study. F. thermalis is one of the most complex prokaryotes. It forms a cellular network in which the main trichome and branches exchange metabolites and regulators via septal junctions. This species can adapt to a variety of environmental conditions, with its photosynthetic apparatus remaining active in a temperature range from 15 to 58 °C. Together with its nitrogen-fixing ability, this allows it to dominate in hot spring microbial mats and contribute significantly to the de novo carbon and nitrogen input. Here, we review the current knowledge on the taxonomy and distribution of F. thermalis, its morphological complexity, and its physiological adaptations to an extreme environment.

中文翻译：

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热菲氏杆菌：研究嗜蓝细菌的重氮营养，光合作用和多细胞性的模型生物。

真正分支的蓝细菌费氏小球藻（也称为Mastigocladus laminosus）在世界各地的温泉中广泛分布。从形态上讲，它早在1837年就已被描述。但是，其分类学位置仍存在争议。F. thermalis属于相同属的嗜温Fischerella的种类，但形式嗜热的单系Fischerella菌株和从温泉序列。它们最近从淡水或土壤真实分支物种中分离出来，并且正在进行的热梯度内部专门化过程使它们成为一个有趣的进化模型。拟南芥是最复杂的原核生物之一。它形成了一个细胞网络，其中主要的毛状体和分支通过间隔连接交换了代谢物和调节剂。该物种可以适应各种环境条件，其光合装置在15至58°C的温度范围内仍保持活性。结合其固氮能力，这使其在温泉微生物垫中占主导地位，并显着促进了从头开始的碳和氮输入。在这里，我们回顾了当前的知识关于F.thermalis的分类和分布，其形态复杂性及其对极端环境的生理适应性。