CTAB提取ATP的生物荧光法快速检测细菌总数准确性研究

The Accuracy of Rapid Detection of Bacterial Count by Bioluminescence Assay with CTAB-Extracted ATP

摘要:

为降低ATP生物荧光法检测费用，本研究采用十六烷基三甲基溴化铵(CTAB)为细菌细胞ATP的提取剂，β-环糊精为中和剂，优化不同食品体系中细菌ATP的提取方法，同时检验CTAB提取ATP的生物荧光法快速检测细菌总数的准确性。结果表明：大肠杆菌、金黄色葡萄球菌、乳酸菌和枯草芽孢杆菌细胞采用CTAB提取出的细菌ATP的发光强度与细菌总数的线性相关性良好，相关系数均在0.92以上。对代表性的果汁、面、肉和奶制品经CTAB处理提取出细菌ATP后，对于细菌总数在103~107 CFU /mL的产品，根据ATP的荧光强度，能准确的判断出细菌总数，且生物荧光法与平板计数法两者检测结果的相关系数达到0.9895。但在原料肉的测定时，提取出的ATP的荧光强度与其细菌总数之间的相关性较差，为提高检测准确性，需要预先采用相关去除体细胞ATP干扰的配套试剂进行处理。

Abstract:

The extraction of ATP was optimized using cetyltrimethyl ammonium bromide (CTAB) and β-cyclodextrin in order to save ATP bioluminescence detection cost, and its accuracy to estimate the total bacteria counts (TBC) in food was investigated by ATP bioluminescence. Results showed the counts of Escherichia coli, Staphylococcus aureus, lactic acid bacteria, Bacillus subtilis were positively associated with the bioluminescence intensity of ATP extracted by CTAB, and the correlation coefficient was more than 0.92. Moreover, the TBC of some products (such as fruit juices, wheat, milk and meat) detected by plate count method were within 103~107 CFU/mL, CTAB extracted ATP bioluminescence was consistently according to bioluminescence intensity. And the correlation coefficient of the two methods reached to 0.9895, but a poor relativity was observed in fresh meat. Therefore, the elimination of somatic cell ATP in fresh meat was essential to estimate the TBC when using CTAB method.