2株樱桃腐败真菌的鉴定及贝莱斯芽孢杆菌对其抑制作用

Identification of two cherry spoilage fungi and inhibition on them by Bacillus velezensis

为了获得绿色、安全的樱桃天然防腐保鲜剂,从腐败的樱桃上分别分离出2株主要的腐败菌,经菌落形态和分子生物学鉴定,初步鉴定为链格孢菌(Alternaria alternata)和总状毛霉(Mucor racemosus),分明命名为BC-1和SC-1。从实验室保存的菌种库中筛选出两株对樱桃腐败菌抑菌效果较好的芽孢杆菌,通过形态学及分子生物学鉴定,初步确定均为贝莱斯芽孢杆菌(Bacillus velezensis),分别命名为KA-2和XK-5。采用LB和landy培养基发酵两株菌,用贝莱斯芽孢杆菌的两种培养基发酵液酸沉后浸泡的方法研究其对樱桃的防腐保鲜作用,发现贝莱斯芽孢杆菌XK-5 landy发酵液酸沉提取物具有更好的防腐保鲜作用。该贝莱斯芽孢杆菌菌株有望作为生产新型绿色、安全的生物防腐保鲜剂的优良菌种。

In order to obtain an environmental friendly and safe natural preservative for cherries,two main spoilage bacteria were isolated from spoiled cherries. After colony morphology and molecular biology identification,they were preliminarily identified as Alternaria alternata and Mucor racemosus,which were named BC-1 and SC-1,respectively. Two strains of Bacillus with good antibacterial effect against cherry spoilage bacteria were screened from strain bank preserved in the laboratory. Through morphological and molecular biological identification,it was preliminarily determined that they were Bacillus velezensis,named Ka-2 and XK-5,respectively. LB and Landy medium were used to ferment two strains of bacteria,and antiseptic and fresh-keeping effects on cherry were studied by acid precipitation and immersion of two kinds of fermented medium broth of Bacillus velezensis. It was found that the acid precipitation extract of Bacillus velezensis XK-5 Landy fermentation broth had better antiseptic and fresh-keeping effects. The strain is expected to be an excellent strain for the production of new environmental friendly and safe bio-preservative.