CO发色罗非鱼片中耐冷腐败菌的分离、鉴定及其生长特性  

Isolation,identification and growth characteristics of psychrotrophic saprophytic bacteria from tilapia fillets treated with carbon monoxide

作　　者：张韵思[1] 郝淑贤[2] 黄卉[2] 张冲溢[1] 罗东红[1] 汪玲玲[1] 

机构地区：[1]华南农业大学生命科学学院,广东广州510642 [2]中国水产科学研究院南海水产研究所,广东广州510300

出　　处：《中国水产科学》2010年第3期570-577,共8页Journal of Fishery Sciences of China

基　　金：国家自然科学基金项目(30671631);农业部"948"引进项目(2006-G640);广东省自然科学基金项目(8451064201001115;06023352);华南农业大学生命科学院大学生博仕奥创新项目资助

摘　　要：从一氧化碳(CO)发色罗非鱼片中分离到耐冷腐败菌LFA04和LFA09,经细菌形态学观察和16SrDNA序列分析初步确定两株均为费氏柠檬酸杆菌(Citrobacter freundii)。菌株LFA04和LFA09生长的适宜温度范围均为4～37℃;适宜的pH范围均为7～9;适宜的NaCl浓度范围分别为0～60g/L和0～40g/L;10℃下的生长代时分别为6.9h和5.87h,25℃下的生长代时分别为2.44h和2.37h。8℃下菌株LFA04和LFA09在鱼片中的腐败规律相似。前3天细菌增殖较快,数量由103CFU/g增至108CFU/g;挥发性盐基总氮(TVB-N)则变化不大,由10.94mg/100g分别变为20.32mg/100g(LFA04)和15.97mg/100g(LFA09)。第3～7天细菌数量维持稳定,而TVB-N值则均迅速增加至70mg/100g以上,鱼肉变软发黏,肉色变绿,散发腐败臭味。常见消毒剂对菌株LFA04和LFA09的致死率实验结果显示,2%次氯酸钠和75%乙醇对菌株LFA04和LFA09的致死率均较高,处理1min时致死率接近或超过70%;2.0mg/L臭氧水对菌株LFA04和LFA09的影响差别较大,浸泡20min时致死率分别为34.8%和71.9%。本研究分离到的2株费氏柠檬酸杆菌能够在冰箱温度下正常生长且能导致鱼肉迅速腐败,其中菌株LFA04经臭氧水处理后存活率较高。因此控制费氏柠檬酸杆菌的污染和繁殖对罗非鱼产品的加工和保鲜尤为重要。Two psychrotrophic and saprophytic strains of LFA04 and LFA09 were isolated from tilapia fillets treated with carbon monoxide（CO）.With the method of morphological observation and 16S rDNA sequence analysis,strains LFA04 and LFA09 were both identified as Citrobacter freundii.The growth characteristics of LFA04 and LFA09 are as follows：Temperature range for growth was 4-37℃;pH was 7-9;Sodium chloride concentration was 0-60 g/L for LFA04 and 0-40 g/L for LFA09;Generation time at 10℃were 6.90 h and 5.87 h,respectively,which at 25℃ were 2.44 h and 2.37 h,respectively.The spoilage regulation of LFA04 and LFA09 on sterilized tilapia fillets was similar at 8℃.In the first three days,the bacterial count increased rapidly,from 10 3 CFU/g to 10 8 CFU/g.And the value of total volatile basic nitrogen（TVB-N）changed little,from 10.94 mg/100 g to 20.32 mg/100 g（LFA04）and 15.97 mg/100 g（LFA09）.In the following four days,the bacterial count kept unchanged,while the TVB-N value of both strains increased to more than 70 mg/100 g,and fillets grew soft and sticky,with green color and off-odors·Lethal rates of strain LFA04 and LFA09 treated with common disinfectant were measured.Strains LFA04 and LFA09 were both sensitive to 75%ethanol and 2%sodium hypochlorite,with the lethal rates reaching or exceeding 70%in one minute.The effects of 2 mg/L ozone water to LFA04 and to LFA09 were different,with the lethal rate being 34.8% and 71.9%after immersed for 20 minutes.Two C.freundii strains isolated in this study could grow well at refrigeratory temperature and lead to tilapia fillets’rapid corruption,and strain LFA04 had high survival rate after treated by ozone water.Therefore,it is very important to control contamination and multiplication of C.freundii strains in tilapia fillet product processing and storing.

关 键 词：CO发色罗非鱼片 费氏柠檬酸杆菌 耐冷菌 鉴定 生长特性 

分 类 号：S983[农业科学—捕捞与储运]