INVESTIGADORES
FERRARI Ana
congresos y reuniones científicas
Título:
EFFECT OF DIFFERENT MEDIA ON PRODUCTION, OXIDATIVE STRESS AND BIOCONTROL EFFICACY OF VISHNIACOZYMA VICTORIAE
Autor/es:
GRAMISCI BETINA; PINO IVANA; QUINTANA DEMIAN; FERRARI ANA; SANGORRIN MARCELA P
Lugar:
San Carlos de Bariloche
Reunión:
Congreso; International Specialized Symposium of Yeast; 2018
Institución organizadora:
ISSY
Resumen:
Vishniacozyma victoriae NPCC 1263 yeast biomass, with antagonistic properties against fungal pathogens of postharvest pear fruits, was produced in a previous work using a not optimized molasses-based medium (NOM) and an optimized medium (OM). The objective of this work was evaluated biomass productions, the stress oxidative tolerance and effectiveness of the control agent obtained from both mediums.Large scale biomass productions were carried out with both conditions NOM (12.8%v/v molasses, 1g/Lurea, 20°C) and OM (9%v/vmolasses, 0.25%p/vKH2PO4, 0.25%p/vZnSO4, 0.25 ppmTiamine and 1g/lurea, at 13°C in a bioreactor (20L). The kinetic parameters Y x/s and μ was calculated (0.24g/g and 0.043h-1 in OM medium and 0.21g/g and 0.034h-1 in NOM medium, respectively) evidencing an improvement in culture parameters with the OM. Cell viability, catalasa activity and intracellular ROS production following exposure of 30 mM H2O2 were evaluated in yeast obtained from two mediums. The highest percentages of viability (100%) was obtained in NOM, the ROS production increased 2-fold in NOM against 5-fold in OM. CAT activity was slightly diminished by H2O2 exposure in cells from OM (55%) and increased from NOM (65%). On the other hand, a highest intracellular content of Trehalose (160 mg/gdw) were obtained in cells from NOM compared with those cells from OM (87 mg/gdw). Finally, the biocontrol capacity of the two biomass preparations was evaluated in wounds in fruit after 6 months of storage. In all cases the yeasts grown in NOM presented better antagonism than those grown in OM. Our findings suggest that resistance to oxidative stress could represent a mechanism by which V. victoriae regulates their viability and biocontrol efficacy when develops in NOM.