Detección y caracterización cinética de una contaminación por Candida tropicalis durante la producción de levadura forrajera

Candida tropicalis was identified as the etiologic agent of a severe contamination detected on an industrial fodder yeast production at the Cuban eastern region. After a detailed diagnostic task on raw material carried out on different factory's sections, protocols to identify the contamination source and to isolate the microorganism were proposed. The identification was by comparison of the internal transcribed spacers ITS1 and ITS4 from 5.8S ribosomal DNA nucleotide sequences. In parallel, propagation of production strain, Candida utilis NRRL Y-660, at lab scale (2.5 l) was performed. Similar results to those observed in the factory concerning to its kinetic behavior in aerobic propagation with contaminated molasses, were detected at this level. The identification and primary kinetic characterization led to the implementation of sanitary and technological measures to bring production at its normal operational conditions as well as the application of prophylactic surveillance methodologies to avoid future contaminations.