A Gram-negative, rod-shaped bacterial strain, NII-0905^T, that was motile by gliding was isolated from soil of a dense forest collected from the Western Ghats of India and its taxonomic position was established. Strain NII-0905^T contained MK-7 as the major menaquinone and anteiso-C_17 : 0, anteiso-C_15 : 0, iso-C_16 : 0 and iso-C_15 : 0 as the major cellular fatty acids. The DNA G+C content of strain NII-0905^T was 51.47 mol%. 16S rRNA gene sequence-based phylogenetic analysis confirmed the placement of strain NII-0905^T in the genus Pontibacter and strain NII-0905^T exhibited 93.9–96.3 % 16S rRNA sequence similarity with type strains of species of the genus Pontibacter. On the basis of genotypic and phenotypic evidence, strain NII-0905^T is considered to represent a novel species of the genus Pontibacter, for which the name Pontibacter niistensis sp. nov. is proposed. The type strain is NII-0905^T (=NCIM 5339^T =CCTCC AA 209057^T).

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.

The taxonomic positions of three Gram-stain-positive, aerobic strains, designated YIM 75722, 75726 and 75728T, and isolated from a soil sample collected from Kurnool of Andhra Pradesh province, India, were assessed using a polyphasic approach. Growth was observed at pH 7.0–10.0 (optimum pH 7.0), 15–28 °C (optimum 28 °C) and 0–8 % (w/v) NaCl (grew without NaCl). Strains showed cylindrical spores with straight-chain morphology on aerial mycelium, but did not reveal sporangium-like structures or fragmentation of the substrate mycelium. Whole-cell hydrolysates of all strains contained galactose and ribose as the diagnostic sugars and meso-diaminopimelic acid as the diamino acid. The predominant menaquinone was MK-9(H4); MK-9 (H6) and MK-10 (H4) were present in smaller amounts. The phospholipid pattern consisted mainly of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine. The major fatty acids were i-C15 : 0, ai-C15 : 0, i-C17 : 0 and ai-C17 : 0. The genomic DNA G+C content was 68.0 mol%. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain YIM 75728T should be placed within the family Pseudonocardiaceae, in which the strain formed a distinct lineage. The combination of phylogenetic analysis, phenotypic characteristics and chemotaxonomic data support the conclusion that strain YIM 75728T represents a novel species of a novel genus of the family Pseudonocardiaceae for which the name Actinorectispora indica gen. nov., sp. nov., is proposed. Strain YIM 75728T ( = DSM 45410T = CCTCC AA 209065T) is the type strain of Actinorectispora indica. Strain YIM 75728T was considered as the type strain over the other two strains based on the highest sequence read length of the strain.