PROBIEN   20416
INSTITUTO DE INVESTIGACION Y DESARROLLO EN INGENIERIA DE PROCESOS, BIOTECNOLOGIA Y ENERGIAS ALTERNATIVAS
Unidad Ejecutora - UE
artículos
Título:
Yeast biocontrol of fungal spoilage of pears stored at low temperature
Autor/es:
ANDREA ROBIGLIO; SOSA, MARIA CRISTINA; LUTZ, MARIA CECILIA; CHRISTIAN LOPES; MARCELA PAULA SANGORRIN
Revista:
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2011 vol. 147 p. 211 - 216
ISSN:
0168-1605
Resumen:
To reduce the use of fungicides, biological control
with yeasts has been proposed in postharvest pears. Most studies of antagonists
selection have been carried out at room temperature. However, in regions like
North Patagonia where fruits are stored at −1/0 °C during 5?7 months the
selection of potential antagonist agents must be carried out at low
temperature. In this study, 75 yeast cultures were isolated from healthy pears
from two Patagonian cold-storage packinghouses. Aureobasidium pullulans, Cryptococcus albidus, Cryptococcus difluens,
Pichia membranifaciens, Pichia philogaea, Rhodotorula mucilaginosa and Saccharomyces cerevisiae yeast species
were identified. Additionally, 13 indigenous isolates of Penicillium expansum and 10 isolates of Botrytis cinerea were
obtained from diseased pears, characterized by aggressiveness and tested for
sensitivity to postharvest fungicides. The yeasts were pre-selected for their
ability to grow at low temperature. In a first biocontrol assay using the most
aggressive and the most sensitive isolate of each pathogen, two epiphytic isolates of A.
pullulans and R. mucilaginosa were
the most promising isolates to be used as biocontrol agents. They reduced the
decay incidence by P. expansum to 33%
and the lesion diameter in 88% after 60 days of incubation in cold. Foreign
commercial yeast used as a reference in assays, only reduced 30% of lesion diameter
in the same conditions. Yeasts were not able to reduce the incidence of B. cinerea decay. The control activity
of the best two yeasts was compared with the control caused by the fungicides
in a second bioassay, obtaining higher levels of protection against P. expansum
by the yeasts. These two regional yeasts isolates could be promising tools for
the future development of commercial products for biological control.