Di3A, Dipartimento di Agricoltura, Alimentazione e Ambiente, University of Catania, via S. Sofia 100, 95123 Catania, Italy.
Di3A, Dipartimento di Agricoltura, Alimentazione e Ambiente, University of Catania, via S. Sofia 100, 95123 Catania, Italy.
Food Microbiol. 2022 Dec;108:104100. doi: 10.1016/j.fm.2022.104100. Epub 2022 Aug 6.
Due to its nutritional characteristics, dried fruit and in particular pistachio is considered an important component in the daily diet. Unfortunately, pistachio nuts can be contaminated during storage with a wide range of pathogenic fungi, including Aspergillus flavus. The present work has evaluated how the use of two yeast strains belonging to the species Wickerhamomyces anomalus and Metschnikowia pulcherrima can inhibit the in vitro and in vivo growth of A. flavus. Both yeast strains demonstrated a good in vitro antifungal activity attributable to a specific mechanism of action, although higher efficacy was evidenced by W. anomalus strain. The production of volatile organic compounds (VOCs) and lytic enzymes was hypothesized as the main mechanisms of action exerted by W. anomalus, while the nutritional competition for iron was assumed as the main biocontrol mechanism for M. pulcherrima. Moreover, from the results of the in vivo test carried out on artificially infected pistachio seeds, it was clear as M. pulcherrima strain showed the same efficacy of W. anomalus in inhibiting the growth and sporulation of A. flavus mold, despite W. anomalus was the most effective strain during in vitro assay. Altogether, these results indicate that both strains could be considered as potential biocontrol agents against A. flavus fungal growth, notwithstanding it is always important considering the tritrophic interaction (yeast-mold- host), which could play a crucial role in determining the final results.
由于其营养特性，干果，特别是开心果，被认为是日常饮食的重要组成部分。不幸的是，在储存过程中，开心果坚果可能会被各种致病真菌污染，包括黄曲霉。本工作评估了两种酵母菌株（异常威克汉姆酵母和美丽假丝酵母）在体外和体内抑制黄曲霉生长的能力。两种酵母菌株均表现出良好的体外抗真菌活性，归因于特定的作用机制，尽管异常威克汉姆酵母菌株表现出更高的功效。挥发性有机化合物（VOCs）和溶酶的产生被假设为异常威克汉姆酵母发挥的主要作用机制，而对铁的营养竞争被认为是美丽假丝酵母的主要生物防治机制。此外，从对人工感染的开心果种子进行的体内试验结果来看，尽管在体外试验中异常威克汉姆酵母是最有效的菌株，但美丽假丝酵母菌株在抑制黄曲霉生长和孢子形成方面表现出与异常威克汉姆酵母相同的功效。总的来说，这些结果表明，尽管始终需要考虑酵母-霉菌-宿主的三营养相互作用，这可能在决定最终结果方面发挥关键作用，但这两种菌株都可以被认为是抑制黄曲霉生长的潜在生物防治剂。
