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The occurrence of ochratoxin A (OTA) has been reported in cereals, feeds and food. Biological control of OTA has been considered as a promising strategy. Our previous study has shown that Yarrowia lipolytica Y‐2 could degrade OTA. In this study, proteome and transcriptome analysis were performed to investigate the possible mechanisms involved in OTA degradation by Y. lipolytica Y‐2 and the responses of this antagonistic yeast to OTA. The results showed that many proteins and genes involved in removal of reactive O2 species were up‐regulated in Y. lipolytica Y‐2 to respond to the oxidative stress caused by OTA. Also, some proteins and genes involved in the removal of generated toxicants under stress condition were up‐regulated to improve tolerance of this antagonistic yeast to OTA stress. Furthermore, some genes encoding transport proteins and multidrug resistance proteins were up‐regulated significantly to transport and expel OTA from cells and alleviate the toxicity to Y. lipolytica Y‐2. Notably, the gene ECM14 (encoding putative metallocarboxypeptidase ECM14) directly involved in OTA degradation was up‐regulated in Y. lipolytica Y‐2 treated with this mycotoxin. To defend against OTA stress, some genes related to tricarboxylic acid cycle were induced by OTA to generate abundant energy for Y. lipolytica Y‐2. Besides, the down‐regulation of some genes involved in DNA replication and repair decreased the ability of Y. lipolytica Y‐2 to repair DNA damage caused by OTA. These results may imply that OTA degradation by this antagonistic yeast was the synergetic effect of multifarious defence responses to OTA stress. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Primarily, chemical pesticides are commonly used to control preharvest and postharvest diseases of fruits and vegetables. However, there is strong public concern regarding the human and environmental health problems that might emanate from the residues of these chemical pesticides. As a result, biocontrol is often preferred due to its safety for humans and animals. The microbial antagonists employed often encounter variable climatic conditions, which affect their efficacy. In this study, the biocontrol efficacy of Hanseniaspora uvarum enhanced with trehalose against Aspergillus tubingensis and Penicillium commune in grapes was investigated. RESULTS: H. uvarum Y3 pretreated with 2.0% w/v trehalose in nutrient yeast dextrose broth (NYDB) before used significantly inhibited the incidence of decay and lesion diameter without affecting the sensory qualities of the grapes stored at either 4 °C or 20 °C. There was also a significant (P < 0.05) increase in the population dynamics of H. uvarum that was pretreated with 2% trehalose compared to that of H. uvarum alone. The in vitro assay on spore germination revealed an inhibition of A. tubingensis and P. commune by 85.6% and 87.0% respectively. Scanning electron microscopy results showed that both untreated H. uvarum and H. uvarum pre‐treated with the 2% w/v trehalose before use inhibited fungal mycelium and development of grape rot. CONCLUSION: The biocontrol efficacy of H. uvarum was enhanced against grape rot caused by A. tubingensis and P. commune. The findings indicate the potential applicability of trehalose in the enhancement of H. uvarum. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The occurrence of patulin in fresh apples and apple products is a great burden from health, safety and economic perspectives. Attempts to prevent patulin accumulation in fruits might lead to the excessive use of fungicides. Therefore, guaranteeing the safety of apple foods is crucial for the international apple industry. Recently, literature revealed that application of antagonistic yeasts and other BCAs have been able to disrupt the process of fungal infection and patulin production in apples. Although, over the years the effect of interaction between BCAs and fungi on patulin production has been reported, the exact mechanism(s) of their action remain unclear. Here, the review focused on toxicology and occurrence of PAT; research advances made over the past few years on the interaction between antagonistic yeast, fruits and patulin-producing fungi; the prevalence of patulin in apple fruits and products and the implications of synthetic-fungicide applications. In addition, attention was focused on the mechanism(s) and the enhancement of the biocontrol efficacy of antagonistic for patulin control. [ABSTRACT FROM AUTHOR]