咸鳓鱼中产组胺菌的分离与鉴定

Isolation and identification of histamine-producing bacteria in salted Chinese herring

针对细菌引起的腌制水产品中生物胺残留问题,胺以传统工艺腌制的咸鳓鱼为对象,利用组胺菌筛选培养基,从不同腌制时期的咸鳓鱼样品中对产组胺微生物进行了筛选,通过16S r DNA测序完成了分离菌株种属鉴定,采用PCR扩增检测了分离菌株组氨酸脱羧酶基因携带情况,并用高效液相色谱(high performance liquid chromatography,HPLC)检测了分离菌株发酵液中组胺的含量。结果表明,分离纯化后共获得32株疑似产生物胺细菌,分布于3个属8个种。葡萄球菌属细菌是优势分离菌株,共计29株,以腐生葡萄球菌数量最多,共16株;24株分离菌株携带组氨酸脱羧酶基因; 23株分离菌株发酵液中测出不同浓度的组胺含量,产组胺菌发酵液组胺平均含量达38. 10μg/m L,其中,1株腐生葡萄球菌菌株发酵液中组胺质量浓度高达100. 21μg/m L,是分离菌株中组胺积累能力最强的菌株。咸鳓鱼生产中产组胺菌的研究,对评估咸鳓鱼的安全性,科学指导其发酵菌株筛选具有理论指导意义。

Accumulation of biogenic amines in fermented seafood products caused by bacterial activity is a serious food safety problem.This study used selective plates to screen histamine-producing bacteria from traditional salted Chinese herring that were collected from different fermentation periods during its production.The isolates were identified by 16S rDNA sequencing.Histidine decarboxylase genes were amplified using polymerase chain reaction(PCR),while the histamine content in the culture supernatant was detected using high performance liquid chromatography(HPLC).The results indicated that thirty-two presumptive histamine-producing isolates were obtained,which were classified into three genera and eight species.Staphylococcus was the predominant genus(twenty-nine strains),with S.saprophyticus was the dominant species(sixteen strains).Histidine decarboxylase genes were detected among twenty-four isolates,and different concentrations of histamine were detected in the cultures of twenty-three isolates.The average content of histamine produced was 38.10μg/mL.Among which,one S.saprophyticus strain produced the highest histamine of 100.21μg/mL.Studying histamine-producing bacteria in salted Chinese herring during its production has theoretical significances in evaluating the safety of salted Chinese herring as well as guiding the selection of fermentation strains scientifically.