Natronosporangium hydrolyticum gen. nov., sp. nov., a haloalkaliphilic polyhydrolytic actinobacterium from a soda solonchak soil in Central Asia

Sorokin, Dimitry Y.; Elcheninov, Alexander G.; Khijniak, Tatiana V.; Zaharycheva, Alicia P.; Boueva, Olga V.; Ariskina, Elena V.; Bunk, Boyke; Spröer, Cathrin; Evtushenko, Lyudmila I.

doi:10.1016/j.syapm.2022.126307

Natronosporangium hydrolyticum gen. nov., sp. nov., a haloalkaliphilic polyhydrolytic actinobacterium from a soda solonchak soil in Central Asia

Title

Natronosporangium hydrolyticum gen. nov., sp. nov., a haloalkaliphilic polyhydrolytic actinobacterium from a soda solonchak soil in Central Asia

Author

Sorokin, Dimitry Y. (TU Delft BT/Environmental Biotechnology; Russian Academy of Sciences)
Elcheninov, Alexander G. (Russian Academy of Sciences)
Khijniak, Tatiana V. (Russian Academy of Sciences)
Zaharycheva, Alicia P. (Russian Academy of Sciences)
Boueva, Olga V. (Leibniz Institute DSMZ)
Ariskina, Elena V. (Leibniz Institute DSMZ)
Bunk, Boyke (Russian Academy of Sciences)
Spröer, Cathrin (Russian Academy of Sciences)
Evtushenko, Lyudmila I. (Leibniz Institute DSMZ)

Date

2022

Abstract

During a cultural diversity survey on hydrolytic bacteria in saline alkaline soils, a hydrolytic actinobacterium strain ACPA39^T was enriched and isolated in pure culture from a soda solonchak soil in southwestern Siberia. It forms a substrate mycelium with rod-shaped sporangia containing 1–3 exospores. The isolate is obligately alkaliphilic, growing at pH 7.5–10.3 (optimum at 8.5–9.0) and moderately halophilic, tolerating up to 3 M total Na⁺ in the form of sodium carbonates. It is an obligately aerobic, organoheteroterophic, saccharolytic bacterium, utilizing various sugars and alpha/beta-glucans as growth substrates. According to the 16S rRNA gene-based phylogenetic analysis, strain ACPA39^T forms a distinct branch within the family Micromonosporaceae, with the sequence identities below 94.5% with type strains of other genera. This is confirmed by phylogenomic analysis based on the 120 conserved single copy protein-based markers and genomic indexes (ANI, AAI). The cell-wall of ACPA39^T contained meso-DAP, glycine, glutamic acid and alanine in a equimolar ratio, characteristic of the peptidoglycan type A1γ'. The whole-cell sugars include galactose and xylose. The major menaquinone is MK-10(H₄). The identified polar lipids consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The polar lipid fatty acids were dominated by anteiso-C_17:0, iso-C_16:0, iso-C_17:0, 10 Me-C_18:0 and C_18:1ω9. Based on the distinct phylogeny, the chemotaxonomy features and unique phenotypic properties, strain ACPA39^T (DSM 106523^T = VKM 2772^T) is classified into a new genus and species in the family Micromonosporaceae for which the name Natronosporangium hydrolitycum gen. nov., sp. nov. is proposed.