Epiphytic Yeasts and Bacteria as Candidate Biocontrol Agents of Green and Blue Molds of Citrus Fruits

Abstract

Overall, 180 yeasts and bacteria isolated from the peel of citrus fruits were screened for their in vitro antagonistic activity against Penicillium digitatum and P. italicum, causative agents of green and blue mold of citrus fruits, respectively. Two yeast and three bacterial isolates were selected for their inhibitory activity on mycelium growth. Based on the phylogenetic analysis of 16S rDNA and ITS rDNA sequences, the yeast isolates were identified as Candida oleophila and Debaryomyces hansenii while the bacterial isolates were identified as Bacillus amyloliquefaciens, B. pumilus and B. subtilis. All five selected isolates significantly reduced the incidence of decay incited by P. digitatum and P. italicum on ‘Valencia’ orange and ‘Eureka’ lemon fruits. Moreover, they were effective in preventing natural infections of green and blue mold of fruits stored at 4 °C. Treatments with antagonistic yeasts and bacteria did not negatively affect the quality and shelf life of fruits. The antagonistic efficacy of the five isolates depended on multiple modes of action, including the ability to form biofilms and produce antifungal lipopeptides, lytic enzymes and volatile compounds. The selected isolates are promising as biocontrol agents of postharvest green and blue molds of citrus fruits.

A super absorbent polymer containing copper to control Plenodomus tracheiphilus the causative agent of mal secco disease of lemon

“…However, as a consequence of growing concerns about the long-lasting environmental sustainability of copper-containing pesticides, the employment of these chemicals in agriculture has been increasingly restricted. The research is consequently driven toward ecologically safe strategies for controlling plant diseases; these include the use of antagonists of pathogens ( Tucci et al, 2011 ; Pérez-Tornero et al, 2012 ; Kalai-Grami et al, 2014 , 2016 ; La Spada et al, 2020 ; Hammami et al, 2022 ), bioproducts ( Pangallo et al, 2017a , b , 2021 ; Belgacem et al, 2019 ; Stracquadanio et al, 2020 , 2021 ; El boumlasy et al, 2021 ), enhancer of natural plant defense mechanisms ( La Spada et al, 2021 ), as well as safe chemicals ( Fallanaj et al, 2016 ). Unfortunately, the management of some plant diseases is complicated by aspects related with the same “nature” of the pathogen, determining the partial or total ineffectiveness of the majority of available means of control.…”

Bioprotective yeasts: Potential to limit postharvest spoilage and to extend shelf life or improve microbial safety of processed foods

“…Interestingly many Candida isolates strongly inhibit plant pathogens. Representatives are, for example, Candida sake CPA-1 [ 67 ], Candida pseudolambica W16 [ 13 ], Candida albicans [ 68 , 69 ], Candida oleophila [ 70 ], Candida pyralidae Y63 [ 71 ], Candida tropicalis [ 72 ], Candida subhashii [ 73 ], which are envisaged as biological control agents to control mold and postharvest diseases in pome, stone fruits as well as citrus fruits. Its antagonistic effect has been tested to be effective in most fruits, including apple [ 74 ], mango [ 75 ], orange [ 41 ], grape [ 76 ], banana [ 77 ], tomato [ 78 ], citrus [ 79 ], litchi [ 80 ], peach [ 13 ], etc.…”

Biocontrol and Probiotic Function of Non-Saccharomyces Yeasts: New Insights in Agri-Food Industry

“…The effectiveness of yeast in preventing food decay has already been established over the last decades, particularly in post-harvest treatments of fruits to control mold decay [ 21 , 122 ]. Recently, Zhang et al [ 16 ] reviewed the recent literature about the antagonistic role of yeasts in the food industry, highlighting their suitable role among various microbial antagonists.…”