摘要
鲭鱼亚目的海洋鱼类在捕获后易产生组胺,导致鲭鱼中毒.为研究组胺消长与微生物的关系,通过平板分离和摇瓶发酵,以荧光光度法测定酶活力,从鲭鱼(Pneumatophorus japonicus)皮肉、内脏和腮中分离筛选组胺降解菌,并对所产组胺降解酶的酶学性质进行研究和分析.结果表明:自内脏中分离筛选到一株组胺降解酶活力较高的革兰氏阴性杆菌,从生长产酶曲线推测该酶为初级代谢产物.该酶反应的最适温度为35℃,最适pH为7.2.在pH 6.0～8.0和温度20～35℃范围内有较好的稳定性.Mn2+、Ca2+、Na-、Mg2+、K+等金属离子存在时酶活力增加,Zn2+、Al3+、Fe3+、Fe2+、Cu2+等金属离子存在时,酶活力下降,在EDTA存在条件下酶活力完全丧失.对其动力学研究表明,在甘氨酸-NaOH缓冲反应体系中,最大反应速度Vmax=156.25 U.mL-1,米氏常数Km=0.22 mg.mL-1.组胺降解菌国内还未见报道,研究结果对进一步研究水产品组胺生物控制技术具有重要意义.
Marine fishes, scombroid species in paticular, are susceptible to producing histamine during processing and storage, as has been reported in incidents of scombroid fish poisoning. To understand the relationship between the producing and degrading of histamine and the microorganism concerned in fish, the bacterials with the capacity of producing histamine-degrading enzyme are screened from skin, flesh, entrails and gills of mackerel （Pneumatophorus japonicus） by plate and shaking flask culture, followed with testing the enzyme activity by pectrofluorimetry method. A gram-negative rod bacterium producing histamine-degrading enzyme is isolated from entrails of mackerel. The enzyme is presumed to be primary metabolite according to the growth and enzyme production curves. The optimum pH and temperature of the crude enzyme activity to histamine is found to be 7.2 and 35 ℃ respectively, and a high stability of the enzyme is observed at 20-35 ℃ and pH 6.0-8.0. It is activated by 5 mmol·L^-1 of ions such as Mn^2＋, Ca^2＋, Na^-, Mg^2＋, K^＋, but inhibited by Zn^2＋, Al^3＋, Fe^3＋, Fe^2＋, Cu^2＋, and completely inhibited by EDTA. The results of kinetic studies show that the kinetic parameter Km of the enzyme was 0.22 mg.mL^-1, and the Vmax of the enzyme is 156.25 U.mL^-1. This paoer presents the first domestic report oh histamine-degrading enzyme producing bacteria, and the study is believed to be important to seek biological control of histamine in food processing in the future.
出处
《宁波大学学报（理工版）》
CAS
2012年第3期1-6,共6页
Journal of Ningbo University：Natural Science and Engineering Edition
基金
宁波市自然科学基金(2010A610014)
宁波大学科研基金(XYL09011
XKI09118
XKI11097)
关键词
鲭鱼
组胺
组胺降解酶
酶学性质
chub mackerel
histamine
histamine-degrading enzyme
enzymatic properties
