Identification and characterization of yeasts in sugarcane silages

Abstract

Aims: To enumerate the micro-organisms and to identify the yeast speciespresent during the ensilage of different sugarcane (Saccharum spp.) cultivars.Method: Samples of sugarcane silage were collected at 10, 20, 30 and 40 daysfrom the start of fermentation. Population levels of lactic acid bacteria (LAB),mesophilic facultative anaerobic (MFA) bacteria, filamentous fungi and yeastswere determined. Nine species of yeasts were classified according to traditionalmethods and confirmed using molecular techniques.Conclusions: LAB dominated the ensiling process of sugarcane, although yeastswere present at relatively high population levels throughout the whole fermen-tation period. The detected species of yeasts varied according to sugarcanecultivar and time of fermentation. Torulaspora delbrueckii was the predominantyeast, followed by Pichia anomala and Saccharomyces cerevisiae.Significance and Impact of the Study: Knowledge of the population of micro-organisms in general, and of yeasts in particular, present during the fermenta-tion of sugarcane is of fundamental importance in the development of moreeffective ensiling processes.