In this study, a genomic approach was employed to evaluate the metabolic potentials and taxonomic classification of the halophilic genus Halarchaeum. Genomic analysis revealed that Halarchaeum members exhibit a predilection for amino acids as their primary energy source in high-salinity environments over carbohydrates. Genome analysis unveiled the presence of crucial genes associated with metabolic pathways, including the Embden-Meyerhof pathway, semi-phosphorylative Entner-Doudoroff pathway, and the urea cycle. Furthermore, the genomic analysis indicated that Halarchaeum members employ diverse mechanisms for osmotic regulation (encompassing both salt-in and salt-out strategies). Halarchaeum members also encode genes to alleviate acid and heat stress. The average nucleotide identity value between Halarchaeum solikamskense and Halarchaeum nitratireducens exceeded the established threshold (95–96%) for defining distinct species. This high similarity suggests a close relationship between these two species, prompting the proposal to reclassify Halarchaeum solikamskense as a heterotypic synonym of Halarchaeum nitratireducens. The results of this study contribute to our knowledge of taxonomic classification and shed light on the adaptive strategies employed by Halarchaeum species in their specific ecological niches.

中文翻译：

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评估嗜盐菌属的代谢、系统发育和分类学分类

在这项研究中，采用基因组方法来评估嗜盐菌属的代谢潜力和分类学分类。基因组分析表明，在高盐度环境中，Halarchaeum 成员表现出对氨基酸作为主要能量来源的偏好，而不是碳水化合物。基因组分析揭示了与代谢途径相关的关键基因的存在，包括 Embden-Meyerhof 途径、半磷酸化 Entner-Doudoroff 途径和尿素循环。此外，基因组分析表明，Halarchaeum 成员采用不同的渗透调节机制（包括盐入和盐出策略）。Halarchaeum成员还编码缓解酸和热应激的基因。Halarchaeum solikamskense 和 Halarchaeum nittireducens 之间的平均核苷酸同一性值超过了定义不同物种的既定阈值 (95–96%)。这种高度相似性表明这两个物种之间存在密切关系，促使有人提议将 Halarchaeum solikamskense 重新分类为 Halarchaeum nittireducens 的异型同义词。这项研究的结果有助于我们对分类学分类的了解，并揭示了Halarchaeum物种在其特定生态位中采用的适应性策略。