Saccharothrix tharensis sp. nov., an actinobacterium isolated from the Thar Desert, India.

The taxonomic provenance of a filamentous actinobacterial strain isolated from a desert soil was established using a polyphasic approach. The strain has chemotaxonomic and morphological properties consistent with its classification in the genus Saccharothrix. It forms a distinct branch in the Saccharothrix 16S rRNA gene tree, related to the type strain of Saccharothrix saharensis (96.7%) but was distinguished readily from it using a combination of phenotypic properties. The genotypic and phenotypic data show that the strain represents a novel species in the genus Saccharothrix, for which the name Saccharothrix tharensis sp. nov. is proposed with the type strain TD-093T (= KCTC 39724T = MCC 2832T).

Characterization of Yuhushiella sp. TD-032 from the Thar Desert and its antimicrobial activity.

During a screening program for antimicrobial compounds from underexplored habitats, a Gram-positive bacterium TD-032, was isolated from arid soil, Thar Desert (India), and analyzed for its morphological, physicochemical, and antimicrobial properties. The 16S ribosomal DNA (rDNA) sequence of the isolate was further studied for the novelty of γ-hyper variable region. TD-032 was grown in large-scale culture, and aqueous and organic solvent extracts analyzed for antimicrobial activity. Culture characteristics showed a lack of diffusible and melanoid pigments. The morphological features were pale yellow aerial mycelium colony color with brownish yellow substrate mycelium and leathery texture. The isolate could grow at 1% concentration of sodium chloride, temperature of 40°C, and a wide range of pH (7.0-12.0). An evaluation for extracellular enzymatic activities showed secretion of gelatinase(s), cellulase(s), and lipase(s). The γ-hyper variable region of 16S rDNA sequence of TD-032 showed 98.33% relatedness to Yuhushiella deserti, indicating a potential new species. Aqueous and ethyl acetate extracts showed antimicrobial activity against Gram-positive and Gram-negative bacteria inclusive clinical isolates. Inhibition of both test bacteria suggests that TD-032 produces a broad spectrum of antimicrobial substances.