Evaluation of yeasts obtained from Antarctic soil samples as biocontrol agents for the management of postharvest diseases of apple (Malus × domestica)

Abstract

Psychrotrophic yeasts were isolated from Antarctic soils, selected based on their ability to grow in apple juice at low temperatures, and were evaluated as potential biocontrol agents for the management of postharvest diseases of apple during cold storage. Among the species recovered, an isolate of Leucosporidium scottii, designated At17, was identified as a good biocontrol agent for blue and gray mold of two apple cultivars. The selected isolate produced soluble and volatile antifungal substances that were inhibitory to apple pathogens. Siderophore production was also demonstrated, but it did not appear to play a role in pathogen inhibition. The selected yeast had the capacity to form a biofilm when grown in apple juice, which is considered an important attribute of postharvest antagonists to successfully colonize wounds and intact fruit surfaces. At17 was resistant to commonly used postharvest fungicides, so application of a combination of low-dose fungicide along with the biocontrol agent could be used as an integrated management practice.

Responses of Yeast Biocontrol Agents to Environmental Stress

“…Therefore, the ability of a yeast species to colonize and develop on a host (commodity) at low temperatures is also an important feature. While this aspect of biocontrol systems has not been studied in detail, Vero et al (50) have explored the use of yeast strains isolated from Antarctic soils as potential biocontrol agents for use under conditions of cold storage (50), and Sangorrín et al recently reviewed the topic of cold-adapted biocontrol yeasts (51). Oxidative stress and low oxygen.…”

Evaluation of yeasts from Tibetan fermented products as agents for biocontrol of blue mold of Nashi pear fruits

“…Antagonistic yeasts are generally isolated from fruit surfaces and fruit wounds (Wilson and Wisniewski, 1989;Wilson et al, 1993). The sources have recently been expended to other environments, such as sea water (Wang et al, 2010) and Antarctic soil (Vero et al, 2013). The main reason for exploring these new sources is that the yeasts in specific geographic areas may have unique characteristics and perhaps be more effective as biocontrol agents against fruit pathogens (Sayago et al, 2012;Vero et al, 2013).…”

“…The sources have recently been expended to other environments, such as sea water (Wang et al, 2010) and Antarctic soil (Vero et al, 2013). The main reason for exploring these new sources is that the yeasts in specific geographic areas may have unique characteristics and perhaps be more effective as biocontrol agents against fruit pathogens (Sayago et al, 2012;Vero et al, 2013). Based on this, our study focused on screening antagonistic yeast from Tibet.…”

Oleaginous Yeasts form Uruguay and Antarctica as Renewable Raw Material for Biodiesel Production

“…Five yeast strains (Leucosporidium scottii At17, Cryptococcus gastricus At4, Rhodotorula mucilaginosa At7, Rhodotorula laryngis At16, Cystofilobasidium infirmominiatum PL1) from the Microbiology Department of Facultad de Química culture collection were also included in this study. The four first strains were isolated from Antarctic soil samples [5], while the fifth was isolated from lemon surface and characterized as a good biocontrol agent of blue mold of oranges [5].…”

“…The nucleotide sequences corresponding to the D1/D2 and the ITS1-ITS2 domains of rDNA of S31 have been deposited in GenBank under the following accession numbers: KM213395 and KM213396 respectively. The other two selected strains (At17 and PL1) were identified in previous studies [5], as Leucosporidium scottii and Cystofilobasidium infirmominiatum, respectively.…”