抗食源性病原菌细菌素的筛选及特性研究

Screening and characterization of bacteriocin against food pathogenic bacteria

中文关键词:  细菌素  食品防腐剂  食源性病原菌

英文关键词:bacteriocin  food preservatives  food pathogenic bacteria

中文摘要:

      目的 筛选一种抗食源性病原菌的细菌素, 并对其稳定性进行研究。方法 以食源性病原菌Bacillus cereus ATCC 14579、Listeria monocytogenes LM201、Listeria monocytogenes LM605为指示菌, 采用琼脂扩散法筛选细菌素产生菌, 通过离子交换树脂法和高效液相色谱法对细菌素进行分离纯化, 通过温度、pH敏感性测试研究该细菌素的稳定性。结果 从来源于窖泥土壤的50株芽胞杆菌中筛选到一株产细菌素菌株T023, 该菌株经16S rDNA序列鉴定为苏云金芽胞杆菌。该菌株所产细菌素对食源性病原菌Bacillus cereus ATCC 14579、Listeria monocytogenes LM201、Listeria monocytogenes LM605的最小抑菌浓度(minimum inhibitory concentration, MIC)分别为2.35、4.69、9.38 μg/mL, 同时, 该细菌素在pH 6~11范围内有抑菌活性并能耐受100 ℃高温。结论 菌株T023所产细菌素对3种食源性病原菌的抑菌活性和耐酸碱性优于Nisin A, 耐热性与Nisin A相当, 该细菌素具有作为食品防腐剂的巨大潜能。

英文摘要:

      Objective To screen a kind of bacteriocin against food pathogenic bacteria, and study its stability. Methods The food pathogenic bacteria Bacillus cereus ATCC 14579, Listeria monocytogenes LM201 and Listeria monocytogenes LM605 were used as indicators to screen bacteriocin-producing strains by agar diffusion assay. The bacteriocin was isolated and purified by ion exchange resin method and high performance liquid chromatography. The stability of the bacteriocin was studied by temperature and pH sensitivity test. Results The strain T023 was screened as bacteriocin-producing strain from 50 pit mud soil samples, and identified as Bacillus thuringiensis by 16S rDNA. The minimum inhibitory concentration (MIC) of the bacteriocin against Bacillus cereus ATCC 14579, Listeria monocytogenes LM201 and Listeria monocytogenes LM605 was 2.35、4.69、9.38 μg/mL, respectively. At the same time, the bacteriocin had antibacterial activity in the range of pH 6-11, and could withstand high temperature of 100 ℃. Conclusion Antibacterial activity against 3 kinds of food pathogenic bacteria and acid-base tolerance of the bacteriocin produced by strain T023 are stronger than Nisin A, and the thermal tolerance of the bacteriocin is essentially comparable to Nisin A, the bacteriocin has great potential as a food preservatives.