Ubiquitousness of Haloferax and Carotenoid Producing Genes in Arabian Sea Coastal Biosystems of India

This study presents a comparative analysis of halophiles from the global open sea and coastal biosystems through shotgun metagenomes (n = 209) retrieved from public repositories. The open sea was significantly enriched with Prochlorococcus and Candidatus pelagibacter. Meanwhile, coastal biosystems were dominated by Marinobacter and Alcanivorax. Halophilic archaea Haloarcula and Haloquandratum, predominant in the coastal biosystem, were significantly (p < 0.05) enriched in coastal biosystems compared to the open sea. Analysis of whole genomes (n = 23,540), retrieved from EzBioCloud, detected crtI in 64.66% of genomes, while cruF was observed in 1.69% Bacteria and 40.75% Archaea. We further confirmed the viability and carotenoid pigment production by pure culture isolation (n = 1351) of extreme halophiles from sediments (n = 410 × 3) sampling at the Arabian coastline of India. All red-pigmented isolates were represented exclusively by Haloferax, resistant to saturated NaCl (6 M), and had >60% G + C content. Multidrug resistance to tetracycline, gentamicin, ampicillin, and chloramphenicol were also observed. Our study showed that coastal biosystems could be more suited for bioprospection of halophiles rather than the open sea.

Highly active and stable protease production by an extreme halophilic archaeon Haloarcula sp. TG1 isolated from Lake Tuz, Turkey

Objective:Isolation of halophilic microorganisms from Çankırı salt mine and Lake Tuz in Turkey to explore versatile protease producers for industry and characterization of protease enzyme from the best protease producer among the isolated strains.Methods:Extreme halophiles were isolated from salt samples of Çankırı salt mine and Lake Tuz. Their protease activities were determined. The isolate with the highest protease activity was characterized. Its protease activity was evaluated in different NaCl concentrations, temperature and pH ranges, and in the presence of different inhibitors and metals. Thermostability and pH stability were also determined.Results:The highest protease producer strain was identified asConclusion:Due to the high activity and stability over a wide range of extreme conditions,