摘要
试验采用微生物杯碟法测定生鲜乳中β-内酰胺酶。使用对青霉素类药物绝对敏感的标准菌株藤黄微球菌,利用舒巴坦的特异性抑制β-内酰胺酶的活性,以青霉素作为指示物,通过对比加入β-内酰胺酶抑制剂与未加入抑制剂的样品所产生的抑菌圈的大小来间接测定样品中是否含有β-内酰胺酶类药物。结果表明:检测用培养基采用单层平板替代双层平板,试验操作更为简单,且确定菌悬液在波长450 nm处吸光度趋于稳定,β-内酰胺酶标准液浓度经检验为4 000 U/mL,同时进行不同生乳检出限的测定,所得结果为生牛乳检出限4 U/mL、生羊乳检出限3 U/m L、生水牛乳检出限1 U/mL。此外,对实际样品进行测定,结果均符合判定要求。
Cylinder plate method was used to determine β-lactamase in raw milk in this research. Micrococcus luteus, which was susceptible to penicillin, was used. Since the vitality of β-lactamase can be inhibited by sulbactam, the β-lactamase-type drugs were indirectly determined by comparing the size of the inhibition zone between samples adding β-lactamase inhibitor and samples without the inhibitor with penicillin as an indicator. The results showed that the single medium plate, instead of the double plate in the test medium, was simpler in experimental operating. And the absorbance value of the suspension was determined to be stable at the wavelength of 450 nm. The concentration of β-lactamase standard solution was 4 000 U/mL. The detection limit of raw milk, raw goat milk, and raw water buffalo milk was 4, 3, and 1 U/mL, respectively. Moreover, the results were in line with the determination requirements when the actual samples were measured.
作者
赵晨
刘慧敏
王加启
郑楠
滕国新
李松励
ZHAO Chen;LIU Huimin;WANG Jiaqi;ZHENG Nan;TENG Guoxin;LI Songli(State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agriculture Sciences,Beijing 100193;Beijing City University,Beijing 100094;Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences,Beijing 100193)
出处
《食品工业》
CAS
北大核心
2018年第12期265-268,共4页
The Food Industry
基金
中央级公益性科研院所基本科研业务费专项资金(2017ywf-zd-21)
产业技术体系(CARS-36)
国家奶产品质量安全风险评估重大专项(GJFP2018008)
北京高等学校高水平人才交叉培养“实培计划”大学生科研训练计划。
