Center of Biotechnology of the Tajik National University, Dushanbe, Tajikistan.
Department of Biological Sciences, University of Bergen, Bergen, Norway.
Microbiologyopen. 2024 Oct;13(5):e70004. doi: 10.1002/mbo3.70004.
Metagenomic analysis was conducted to assess the microbial community in the high-altitude Tamdykul geothermal spring in Tajikistan. This analysis yielded six high-quality bins from the members of Thermaceae, Aquificaceae, and Halothiobacillaceae, with a 41.2%, 19.7%, and 18.1% share in the total metagenome, respectively. Minor components included Schleiferia thermophila (1.6%) and members of the archaeal taxa Pyrobaculum (1.2%) and Desulfurococcaceae (0.7%). Further analysis of the metagenome-assembled genome (MAG) from the Desulfurococcaceae family (MAG002) revealed novel taxonomy with only 80.95% closest placement average nucleotide identity value to its most closely related member of the Desulfurococcaceae family, which is part of the Thermoproteota phylum comprising hyperthermophilic members widespread in geothermal environments. MAG002 consisted of 1.3 Mbp, distributed into 48 contigs with 1504 predicted coding sequences, had an average GC content of 41.3%, a completeness and contamination rate of 98.7% and 2.6%, respectively, and branched phylogenetically between the Ignisphaera and Zestosphaera lineages. Digital DNA-DNA hybridization values compared with Ignisphaera aggregans and Zestosphaera tikiterensis were 33.7% and 19.4%, respectively, suggesting that this MAG represented a novel species and genus. Its 16S rRNA gene contained a large 421 bp intron. It encodes a complete gluconeogenesis pathway involving a bifunctional fructose-1,6-bisphosphate phosphatase/aldolase; however, the glycolysis pathway is incomplete. The ribulose monophosphate pathway enzymes could be used for pentose synthesis. MAG002 encodes several hydrogen-evolving hydrogenases, with possible roles as hydrogen sinks during fermentation. We propose the name Zestomicrobium tamdykulense gen. nov. sp. nov. for this organism; it is the first thermophilic genome reported from Tajikistan.
采用宏基因组分析方法评估了塔吉克斯坦高海拔 Tamdykul 温泉的微生物群落。该分析从 Thermaceae、Aquificaceae 和 Halothiobacillaceae 成员中获得了 6 个高质量的宏基因组 bin，分别占总宏基因组的 41.2%、19.7%和 18.1%。次要成分包括嗜热栖热菌（1.6%）和古菌 Pyrobaculum（1.2%）和 Desulfurococcaceae（0.7%）的成员。对来自 Desulfurococcaceae 科的宏基因组组装基因组（MAG）的进一步分析（MAG002）揭示了一种新的分类法，其与最密切相关的 Desulfurococcaceae 科成员的平均核苷酸同一性值仅为 80.95%，而最密切相关的成员属于 Thermoproteota 门，包含广泛分布于地热环境中的高温嗜热成员。MAG002 由 1300 千碱基对组成，分布在 48 个 contigs 中，有 1504 个预测编码序列，平均 GC 含量为 41.3%，完整性和污染率分别为 98.7%和 2.6%，在 Ignisphaera 和 Zestosphaera 谱系之间分支进化。与 Ignisphaera aggregans 和 Zestosphaera tikiterensis 的数字 DNA-DNA 杂交值分别为 33.7%和 19.4%，表明该 MAG 代表了一个新的物种和属。其 16S rRNA 基因含有一个大的 421bp 内含子。它编码一个完整的糖异生途径，涉及双功能果糖-1,6-二磷酸磷酸酶/醛缩酶；然而，糖酵解途径是不完整的。核酮糖-1,5-二磷酸途径的酶可用于戊糖合成。MAG002 编码几种产氢氢化酶，可能在发酵过程中作为氢汇发挥作用。我们建议将该生物命名为 Tamdykul 嗜热菌属。nov. sp. nov.，这是首次从塔吉克斯坦报道的耐热基因组。
