Yeasts diversity in Brazilian Cerrado soils: Study of the enzymatic activities

Abstract

A total of 307 yeasts strains were isolated from native Cerrado (Brazilian Savannah) soils collected at Passos, Luminarias and Arcos areas in Minas Gerais State, Brazil. The soils were chemically characterized. Ten yeast genera (Candida, Cryptococcus, Debaryomyces, Kazachstania, Kodamaea, Lindnera, Pichia, Schwanniomyces, Torulaspora and Trichosporon) and 23 species in both rainy and dry seasons were identified. All genera were abundant during the dry season. The pH values of the soil from the Passos, Luminarias and Arcos areas varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium and organic matter in the soils among the studied areas. The Arcos area contained large amounts of aluminum during the rainy season and both hydrogen and aluminum in the rainy and dry seasons. The yeast populations identified seemed to be unaffected by the high levels of aluminum in the soil. The API ZYM® (BioMerieux, France) system was employed to characterize the extracellular enzymatic activity profiles of the yeast isolates. The results of the API ZYM® test showed differences in the extracellular enzyme profiles among the yeast species. Some isolates that belong to the same species showed enzymatic profiles that differed from one another. Our study is the first to describe yeasts isolated from Brazilian Cerrado soils from Minas Gerais State and demonstrates their ability to produce enzymes that may be of potential industrial interest. Key words: Enzymes, Brazilian soils, yeasts biodiversity, Cerrado.