Basifimbria (Dicyma) peruviana, una especie psicrófila de la Antertida Argentina

R. COMERIO; G. VAAMONDE; S. DE HOOG

Mar del Plata

Congreso; VI Congreso Latinoamericano de Micología; 2008

Asociación Latinoamericana de Micología

Subject: S3DEHOOG Nombre del archivo: S3DEHOOG.doc Basifimbria peruviana, a psicrophilic isolate from Argentine Anctarctica. Basifimbria peruviana, un aislamiento psicrófilo de la Antártica Argentina. Comerio R2, Vaamonde G3., De Hoog S1  1Centraalbureau voor Schimmelcultures; 2Instituto de Microbiología y Zoología Agrícola INTA; 3Depto. De Química Orgánica FCEyN-UBA. Basifimbria peruviana is a mitosporic species that could be related to Xylariales. As it is a not very frequent-isolated taxon, little is known about its physiology. The aim of this work was to study the influence of temperature on the growth rate of an Anctarctic isolate: B. peruviana CBS 110210. Spore suspensions (106 spores/ml; tween 80, 0.05 %) were inoculated with a needle in one central point on Malt Extract Agar plates (9 mm diam.). Triplicates were made for each temperature point. The cultures were incubated at 0ºC, 10ºC, 15ºC, 20ºC, 25ºC and 30ºC. Colony diameters were measured and radial growth rates (kr) were calculated as the linear regression of the growth curve. The isolate exhibits a psychrofilic behaviour since it has optimum temperature at about 15°C and do not grow above 25°C. Furthermore, the curve declines more rapidly above the optimum temperature than bellow it. As the temperature decreases from the optimum the growth rate slows but the microorganism shows a considerable growth rate at temperature as low as 0°C (kr = 3.5 mm day-1). The ability of B. peruviana of growing at low temperature could be a consequence of an adaptative process which have permitted the fungi to endure in the extreme environment. To date, strains of this species are known from the high Andes and from the Antartic.