秋刀鱼中组胺菌的分离及其理化性质研究

Isolation of Histamine-Forming Bacteria and Their Physicochemical Properties Analysis of Pacific Saury(Cololabis saira)

采用不同选择性培养基对秋刀鱼组织中的产组胺菌进行筛选分离,通过理化性质分析对筛选出的菌株进行初步鉴定,同时研究了温度和pH值对不同菌株组胺产生能力的影响。结果显示,分离获得5株产组胺菌,分别命名为菌株1、菌株2、菌株3、菌株4、菌株5,经鉴定依次属于哈夫尼菌属(Hafnia)、志贺氏菌属(Shigella)、变形菌属(Proteus Hauser)、沙雷铁氏菌属(Serratia)和假单胞菌属(Pseudomonas)。5株菌在4~36℃温度下及pH值4.5~8.5范围内均能产生组胺,最适温度分别为20、36、36、20和25℃,最适pH值分别为8.5、7.5、6.5、6.5、7.5,在适宜培养条件下组胺产生能力均可超过20mg/mL。4℃低温和pH值4.5条件下5株菌组胺产生能力均显著(p<0.05)降低,但仍能保持较高的水平。以上结果为秋刀鱼组胺菌的控制提供了理论依据。

This study was conducted to isolate and identify histamine-forming bacteria (HFB) in Pacific saury (Cololabis saira) with the aid of different selective mediums as well as the physicochemical properties analysis.Meanwhile,the impact of different temperature and pH value on the histamine-forming capacity of the isolated bacteria were also investigated.The results showed that five HFB were isolated and identified from Pacific saury,which were named as strain 1,strain 2,strain 3,strain 4 and strain 5.They were likely belong to Hafnia,Shigella,Proteus Hauser,Serratia and Pseudomonas,respectively.All the HFB could produce histamine in the range of 4-36 ℃ and the pH 4.5-8.5.The optimum temperature for strain 1,strain 2,strain 3,strain 4 and strain 5 to produce histamine were 20,36,36,20 and 25 ℃,respectively,while the optimum pH value were 8.5,7.5,6.5,6.5 and 7.5,respectively.Under the optimum conditions,the histamine-forming capacity of all the HFB was over 20 mg/mL.Although low temperature (4 ℃) and acidic environment significantly decreased the histamine-forming capacity of the HFB,the histamine concentration could maintain a relatively high level.These results provide a theoretical basis for controlling the level of HFB in Pacific saury.