Extracellular chitinase activity has been
reported in Cryptococcus species , but here we observed this activity in M. psychrophila, Sp. salmonicolor, Metschnikowia sp., Leuconeurospora sp. and D. fristingensis. We detected cellulase and chitinase activities in yeasts species that have not been described from cold regions, probably because our sampling sites included areas with vegetation and animal contact and/or were located close to the sea. Cellulose is one of the most abundant Selleckchem BX-795 carbohydrates produced by plants  and chitin is the most abundant renewable polymer in the ocean, where it constitutes an important source of carbon and nitrogen . Furthermore, significant quantities of lipids exist in phytoplankton  and in sediments of this region , which can explain the high incidence of lipase activity found in the yeasts. All of the extracellular enzyme activities analyzed in this work are potentially useful to industry: amylases in food processing, fermentation and pharmaceutical industries; cellulases and pectinases in textiles, biofuel processing and clarification of fruit juice; esterase in the agro-food industries; lipases and proteases in food and see more beverage processing, detergent this website formulation and environmental bioremediations; chitinases in biocontrol and treatment of chitinous waste; xylanase
as a hydrolysis agent in biofuel and solvent industries [10, 39–41]. Conclusions Similar to previous reports of microorganisms isolated from cold environments, the yeasts isolated in this work are predominately psychrotolerant. Rapid identification/typing of yeasts was achieved through the use of D1/D2 and ITS regions; however, other physiological and biochemical tests are required for accurate species/strains definition. The diversity of extracellular enzyme activities in the yeasts, and hence the diversity of compounds that may be degraded/transformed, reflects the importance of the yeast community mafosfamide in nutrient recycling in the Antarctic regions. In addition, studies about the adaptation of the different yeast species to adverse conditions (temperature, freeze-thaw, UV radiation, nutrient availability,
competence, etc.) could shade light on the evolution of molecular mechanisms (carbon metabolisms, cell wall and protein structure, etc.), which are implicated in facilitating that accommodation. As an example, changes in protein structure are fundamental to allow conformation of the cytoskeleton, enzyme activity, etc. The Antarctic yeast isolates may potentially benefit industrial processes that require a high enzymatic activity at low temperatures, including bread, baking, textile, food, biofuel and brewing industries. Methods Sampling sites All sampling sites were located on King George Island (62°02′S 58°21′W/62.033°S 58.35°W), the major island of the Shetland South Archipelago (Figure 1). A total of 34 soil and 14 water samples were collected in January of 2009.