鲜切苦菊、生菜和紫甘蓝上假单胞菌的分离鉴定及其噬菌体的初步筛选

Isolation and Identification of Pseudomonas spp. from Fresh-cut Chrysanthemum, Lettuce, and Purple Cabbage and Preliminary Screening of Their Phages

摘要:

鲜切蔬菜是人类摄取矿物质和维生素的重要来源，假单胞菌是鲜切蔬菜上的主要腐败菌。为了控制鲜切蔬菜中假单胞菌的污染，该研究采用假单胞菌培养基和16S rRNA基因序列分析，对鲜切苦菊、生菜和紫甘蓝中的假单胞菌进行分离鉴定，筛选得到2株铜绿假单胞菌（Pseudomonas aeruginonas）、1株荧光假单胞菌（Pseudomonas fluorescens）和1株湖南假单胞菌（Pseudomonas hunanensis）。将铜绿假单胞菌和荧光假单胞菌这两种腐败菌分别回接到三种鲜切蔬菜中，证实了铜绿假单胞菌致腐能力更强，并发现在同种假单胞菌影响下的鲜切蔬菜腐败速度从快到慢为：苦菊、生菜、紫甘蓝。利用双层琼脂平板法，分别以铜绿假单胞菌和荧光假单胞菌为宿主筛选分离得到了噬菌体vB_Pae_503-1和vB_Pfl_503-2，经抑菌实验证明噬菌体能有效抑制假单胞菌的生长。

Abstract:

Fresh-cut vegetables are an important source of minerals and vitamins for human beings; Pseudomonas spp. are mainly responsible for spoilage of fresh-cut vegetables. To control Pseudomonas spp. contamination of fresh-cut vegetables, Pseudomonas spp. culture media and 16S rRNA gene sequence analysis were used to isolate and identify Pseudomonas spp. in fresh-cut bitter chrysanthemum, lettuce, and purple cabbage. Two strains of Pseudomonas aeruginonas, one strain of Pseudomonas fluorescens, and one strain of Pseudomonas hunanensis were screened. P. aeruginosas and P. fluorescens were re-inoculated into the three types of fresh-cut vegetables respectively, and results confirmed that P. aeruginosa had stronger spoilage ability. Spoilage rate under the influence of the same Pseudomonas spp. decreased in the following order: bitter chrysanthemum > lettuce > purple cabbage. The phages vB_Pae_503-1 and vB_Pfl_503-2 were screened and isolated by the double-layer agar plate method when P. aeruginosa and P. fluorescens were respectively used as the hosts. Results of bacteriostatic experiments indicate that phages can effectively inhibit the growth of Pseudomonas spp.