Isolation and Identification of Spoilage Fungus in Plum and Antifungal Effects of Antifungal Agents on the Spoilage Fungus

Abstract

In this study, the spoilage fungi were isolated and identified from “Cuihong” plum, “Qingcui” plum, and “Yinhong” plum. Then the antifungal effect of ε-polylysine, natamycin, and sodium dehydroacetate on the isolated plum spoilage fungus was studied by disc diffusion method. The results showed that, seven kinds of fungus (Pichia occidentalis, Pichia kluyveri, Pichia terricola, Candida sp., Saturnispora diversa, Saccharomycopsis crataegensis, Saccharomyces cerevisiae) were isolated. The antifungal activity was gradually enhanced with the increase of the concentration of the antifungal agents. Among them, the highest tolerance to natamycin was showed in Saccharomycopsis crataegensis with a minimum inhibitory concentration (MIC) of 0.4 mg/mL. Besides, the tolerance of Pichia occidentalis to ε-polylysine and sodium dehydroacetate were higher than that of the other spoilage fungus, and the corresponding MIC were 0.06 and 0.10 g/mL, respectively. Therefore, the spoilage fungus with the highest tolerance to antifungal agents could be selected as the indicator fungus according to the type of antifungal agents and plums, which would provide a theoretical basis for further application of chemical methods and compound film methods on preservation of plums.

Keywords

• plum
• spoilage fungus
• antifungal effect
• ε-polylysine
• natamycin
• sodium dehydroacetate