SRA

Environments with extremely water depravation are critical for microbial growth. The thermodynamic parameter that defines the amount of free water in an aqueous solution is called water activity (aw), and it is severely restricted at aw < 0.90.Solutes like NaCl, KCl and sorbitol classified as kosmotropes (water-structure makers), can reduce aw causing effects on the growth of microorganisms, osmotic stress, and cytotoxicity. This condition leads to metabolic and phenotypical changes in order to restore the osmotic balance of the cell.For those reasons, the aim of this study was to determine potential differences in the molecular, metabolic and phenotypical responses of A. sydowii (a well-adapted pathogen), at low aw imposed by kosmotropes compounds. Transcriptomics allowed us to identify the genes involved in the cellular response of this fungi to extreme water deprivation imposed by 3 kosmotropes (NaCl, KCl and sorbitol). Differences in the utilization of different substrates were determined using the modern Biolog FF Microplate system. We also analyze the micro- and macro-morphological characters of A. sydowii in these conditions.To the best of our knowledge, this is the first comparative study of a halophilic fungus in the presence of saturated amounts of NaCl, KCl and sorbitol.