Yeast biocontrol against green mold in pear orange postharvest

Abstract

The objective of this study was to evaluate the efficiency of the enzyme β-1, 3-
glucanase and the mechanisms of action produced by yeasts in the biological control of
green mold in post-harvest oranges of the pear variety. The Fully Casualized Delineation
(FCD) was used. The results were submitted to analysis of variance (ANOVA), in triplicate,
compared with Tukey's test at a 5% probability level (p < 0.05), using the statistical
software Sisvar. It was found that the killer activity was observed in 85.7% of the yeasts
evaluated. The yeast Candida peltata URM4681 showed better production of β-1.3-
glucanase, between 1.071 and 5.422 µg mL -1 . A factorial delineation 2 3 was used in a
medium composed of yeast extract, soybean extract and meat extract to increase
enzymatic production, reaching an increase of 4.351 times comparing the assay of lower
and higher activity. The in situ assays showed a reduction in the number of infected fruits
treated with the enzymatic extract, being on average 78.5% when compared with the
control treatment (distilled water). As for sporulation, the enzymatic extract, which had an
average of 8.4 spores, did not differ statistically from the IMZ and TBZ fungicides, both in a
preventive and curative manner. Regarding the severity of the disease, it was noted that
the fruits treated with enzymatic extract, had an average damage of 7.57 %, also not
differing statistically from fungicides, both preventive and curative. Our studies suggest
that C. peltata URM4681, makes this a good candidate for biocontrol against green mold.