ORIGINAL RESEARCH article
Front. Microbiol.
Sec. Biology of Archaea
Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1640521
This article is part of the Research TopicInvestigating Halophilic Archaea: From Ecological Insights to Industrial InnovationsView all articles
Natrarchaeobius versutus sp. nov., and Natrarchaeobius oligotrophus sp. nov., chitinotrophic natronoarchaea from hypersaline soda lakes, and functional genome analysis of the Natrarchaeobius species
Provisionally accepted
- 1Federal Center Research Fundamentals of Biotechnology (RAS), Moscow, Russia
- 2Moscow Center for Advanced Studies, Moscow, Russia
- 3Technische Universiteit Delft Afdeling Biotechnologie, Delft, Netherlands
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So far, polysaccharide-degrading natronoarchaea were poorly studied, but for the last decade understanding of their diversity and metabolic potential has been significantly expanded. In this work, two natronoarchaeal strains, enriched from oxic sediment samples of the soda lakes of Wadi an Natrun in Egypt (AArcel7) and Kulunda steppe in Russia (A-rgal3), were characterized. AArcel7 was enriched in a consortium with cellulotrophic strain AArcel5, currently classified as Natronobiforma cellulositropha, while A-rgal3 dominated an enrichment culture with rhamnogalacturonan. Cells of both strains are polymorphic, from motile flat rods to nonmotile cocci. They are aerobic heterotrophs able to grow on chitin and several other carbohydrates. Both strains thrive within a salinity range from 2.5 to 4.5 M total Na + , with optimal growth at 3.5-4 M, and are moderately alkaliphilic with an optimum pH at 8.5-9.0 (AArcel7) and 9.2-9.5 (A-rgal3). Genome-based phylogenetic analysis demonstrated that these isolates are forming new species lineage in the chitin-specialized genus Natrarchaeobius. An in-depth study of Natrarchaeobius genomes allowed us to identify several genes that potentially enable them to hydrolyze chitin and to metabolize N-acetylglucosamine (GlcNAc) which has not been investigated previously in the chitin-utilizing natronoarchaea. On the basis of physiological, phylogenetic and genomic analyses, strains AArcel7 and A-rgal3 are suggested to form a novel species, Natrarchaeobius versutus sp. nov. with AArcel7 T (DSM 119357 = UNIQEM U973) as the type strain. Furthermore, strain AArcht7 T , formerly classified in the type species of the genus Natrarchaeobius, is proposed to be reclassified as Natrarchaeobius oligotrophus (DSM 119677 = UNIQEM U967).
Keywords: Natronoarchaea, soda lakes, Natrarchaeobius, Chitin, Chitinase, Glycoside Hydrolases
Received: 04 Jun 2025; Accepted: 14 Jul 2025.
Copyright: © 2025 Tulenkov, Elcheninov and Sorokin. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Alexander G. Elcheninov, Federal Center Research Fundamentals of Biotechnology (RAS), Moscow, Russia
Dimitry Y Sorokin, Federal Center Research Fundamentals of Biotechnology (RAS), Moscow, Russia
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