Characteristics of Wild Yeast Killer from Nahuel Huapi National Park (Patagonia, Argentina)

Silvia Brizzio, Marta van Broock

Laboratorio de Microbiología, Centro Regional Universitario Bariloche, Universidad Nacional del Comahue. and Conicet, Quintral 1250 (8400), Bariloche, Rio Negro, Argentina

Article history:

Received July 28, 1997 
Accepted November 11, 1998

Key words:

killer yeasts, terrestrial environments, aquatic environments


The aim of this study was the survey of killer yeasts in natural environments at the Nahuel Huapi National Park in the Subantartic Forest, Northwestern Patagonia. One hundred and twenty three yeast isolates were analysed. Yeasts associated with nectarine flowers, sugary wild fruits and sporangia of the fungus Cyttaria spp., and glacial-origin lakes freshwater samples were screened in their killing activity against the sensitive yeast tester strain Candida glabrata NCYC 388. The sensitivity to known toxins (K1 to K10) was tested against yeast isolates. Three of the 28 cultures isolated from nectar shmued killer activity, whereas none was detected in those derived from fruits or freshwater samples. The 38% of all tested strains were sensitive to one or more toxins. The broadest spectrum of sensitivity was observed in cultures from nectar samples, while 57% of the yeasts isolated from fruits were neutral. The latter were also prevalent among yeasts from freshwater samples. 

*Corresponding author: correspondence should he addressed to: Conicet (Consejo Nacional de Investigaciones Cientificas y Tecnologicas de la Republica Argentina)