Biodiversity and biotechnological potential of cultivable Halophilic bacteria from Slana voda (Oravska Polhora, Slovakia) natural salt spring

Abstract Halophilic microorganisms are of immense importance in various fields of biotechnology. There is a multitude of actual or potential applications in the research of environmentally friendly applications in biodegradation, decolorization, food biotechnology, and biopolymers production. Thirty-eight strains of halophilic bacteria were isolated from the Slana voda (Slovakia, Central Europe) natural salt spring, with a tolerance of up to 20% of NaCl. The Halomonas genus accounted for more than 35% of the cultivable microbiota, followed by Shewanella and Pseudoaltermonas genera. More than 55% of bacterial isolates were able to produce at least one of the tested hydrolases (cellulase, lipase, amylase, protease) and three of them were positive for all four enzyme activities. Bacterial isolates showed a relatively high ability to degrade synthetic dyes, namely congo red, crystal violet, malachite green, methylene blue, methyl red, and safranin (5.26, 42.11, 44.74, 63.16, 92.18, and 18.42% of isolates respectively). Interestingly only a small overlap was observed between the isolates producing extremozymes and the isolates demonstrating decolorizing activity.