For the low NaCl concentration, two varieties of the genusWallemia(Wallemia muriaeandWallemia ichthyophaga) were cultivated at 5% NaCl (aw= 0.962) and 10% NaCl, respectively, because of the obligate need for NaCl in the medium; NaCl was then added to 17% (aw= 0.873), with glucose tested for these two species at 40% and 55%, respectively. was observed. Increased salt concentrations resulted in higher hemolytic activity, particularly within varieties dominating the salterns. The appearance of antibacterial potential under stress conditions was seen in the related pattern of fungal varieties as for hemolysis. The active components specifically affected the growth of the Gram-positive bacterium tested,Bacillus subtilis. None of the components tested showed inhibition of acetylcholinesterase activity. Keywords:hypersaline environments, black candida, NaCl, secondary metabolites, hemolysis, antibacterial activity == 1. Intro == As crystalline salt (NaCl) is generally considered to Levomefolate Calcium be hostile to most forms of existence, it has been used for centuries as a food preservative. However, halophilic and halotolerant microorganisms can contaminate food that is maintained with salt, and they can also inhabit natural hypersaline environments around the world, such as salt lakes and solar salterns. These microorganisms can adapt to intense concentrations of NaCl, and often to high concentrations of additional ions [1], and also to extremely low water activity (aw), due to the chemical bonding of water to NaCl [2]. The great majority of studies of halophilic and halotolerant microorganisms have been dedicated to halophilic bacteria and archaea [35], and to only one eukaryotic varieties, the algaDunaliella salina[6], as it has Levomefolate Calcium been considered that additional eukaryotic organisms cannot adapt to these intense conditions [7]. Black yeasts were 1st reported to be active inhabitants of brine in solar salterns in 2000 [1]. Since then, many fresh fungal varieties and varieties previously known only as pollutants of food maintained with high concentrations of salt or sugar have been found out in hypersaline environments around the globe [812]. These fresh ecological findings possess not only improved our understanding of complex microbial processes in these natural hypersaline environments, but they have also contributed to the not yet fully acknowledged demonstration that food can be contaminated with potentially mycotoxigenic fungi via the salt (or sugars) used as the preservative. Remarkably, many fungal varieties that were 1st found in hypersaline environments were later recognized in polythermal Arctic glaciers [8,13,14]. Therefore, despite the intense variations in physical conditions between glaciers and solar salterns exposed to the heat and UV of strong sunlight, the common essential parameter for varieties found both in Arctic glaciers and in Mediterranean salterns is the lowaw, which is definitely associated with glaciers due to ice formation. In general, marine organisms represent a wide source of yet undiscovered compounds that, besides unprecedented chemical structures, often possess interesting biological activities. These could Levomefolate Calcium find their use in medicine, pharmaceutics, market, and additional fields of human being activities. The production of biologically active compounds in marine-, dirt-, and food-derived fungi has been the subject of several investigations over the last 10 years (observe also HUP2 below); however, there have been no such investigations focusing on halophilic and halotolerant fungi. Thus, the aim of the present study was to investigate stable fungal areas both in hypersaline waters of solar salterns and in subglacial snow in relation to the synthesis of bioactive metabolites with hemolytic, antibacterial, and acetylcholinesterase (AChE) inhibition activity. The finding of fresh antibiotics is one of the most important goals in biomedical study, since the appearance of multiresistant bacterial strains urged the search of fresh strategies for treatment of bacterial infections. As to AChE inhibitors, these substances could find their use in treating disorders like Alzheimer disease, myasthenia gravis and glaucoma. Substances exerting above-selected biological activities may also have important ecological tasks, as they could serve in territorial competition, or in safety against additional hypersaline varieties. In this regard, hemolytic and antimicrobial compounds could take action against protozoa and bacteria, while AChE inhibitors might be directed against higher organisms having a developed nervous system..