李子腐败真菌的分离鉴定及抑菌剂对其抑制效果

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

本文对脆红李、青脆李和茵红李三种李子的腐败真菌进行分离鉴定,并采用滤纸片扩散法研究了ε-聚赖氨酸、纳他霉素、脱氢乙酸钠对分离得到的李子腐败真菌抑制效果。结果表明,共分离出西方毕赤酵母(Pichia occidentalis)、克鲁维毕赤酵母(Pichia kluyveri)、特立科拉毕赤酵母(Pichia terricola)、假丝酵母(Candida sp.)、赤霞珠葡萄表皮酵母(Saturnispora diversa)、复膜孢酵母属(Saccharomycopsis crataegensis)、酿酒酵母(Saccharomyces cerevisiae)7种腐败真菌。随着抑菌剂浓度的升高,抑菌效果均逐渐增强。其中,复膜孢酵母对纳他霉素的耐受程度最高,纳他霉素对复膜孢酵母的最小抑菌浓度为0.4 mg/mL;西方毕赤酵母对ε-聚赖氨酸与脱氢乙酸钠的耐受程度均大于其它腐败真菌,二者的对应最小抑菌浓度分别为0.06、0.10 g/mL。在今后对李子进行化学保藏、复合涂膜保鲜等研究时,可依据抑菌剂和李子的种类选择对抑菌剂耐受度最高的腐败菌作为指示菌。本文为今后李子进行化学保藏、复合涂膜保鲜提供了理论依据。

In this study,the spoilage fungi were isolated and identified from“Cuihong”plum,“Qingcui”plum,and“Yinhong”plum.Then the antifungal effect ofε-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 toε-polylysine and sodium dehydroacetate were higher than that of the other spoilage fungus,and the corresponding MIC were 0.06 and0.10 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.