Protein Particulate Retention and Microorganism Recovery for Rapid Detection of Salmonella
Protein Particulate Retention and Microorganism Recovery for Rapid Detection of Salmonella
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DOI：
10.1002/btpr.2468
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发表时间：
2017-05-01
影响因子：
2.9
通讯作者：
Ladisch, Michael R.
中科院分区：
文献类型：
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作者：
Ku, Seockmo;Kreke, Thomas;Ladisch, Michael R.
快速检测碎肉中的沙门氏菌需要在 8 小时内将活微生物达到可通过 PCR、免疫测定或类似技术检测到的水平。此前，我们采用中空纤维膜微滤，通过酶处理和预过滤相结合，快速处理和浓缩食品提取物中的活细菌，以防止中空纤维膜堵塞或污染。然而，扫描电子显微镜和酶水解产物的粒度分析表明，酶处理后过滤导致亚微米颗粒形成并被截留在预过滤介质中，从而保留了约 80% 的细菌。酶处理之前的过滤导致形成由保留在过滤器表面上的蛋白质颗粒组成的滤饼，同时促进较小的微生物通过过滤器，将它们与颗粒分离。随后对滤液进行酶处理，得到的提取物在不到一小时的时间内进行了微滤，同时将提取物中的活微生物浓缩了 500 倍。将含有 1-20 CFU/mL 的肠沙门氏菌细胞接种到火鸡汉堡中，由尖刺细胞和火鸡汉堡样品中已存在的细胞组成，迅速达到可通过常规 PCR 和 BAX (R) PCR 测定检测到的水平。从样品处理到肠沙门氏菌检测的整个过程在不到8小时内完成。 (c) 2017 年美国化学工程师生物技术学会。
The rapid detection of Salmonella in ground meat requires that living microorganisms be brought to levels detectable by PCR, immunoassays, or similar techniques within 8 h. Previously, we employed microfiltration using hollow fiber membranes to rapidly process and concentrate viable bacteria in food extracts through a combination of enzyme treatment and prefiltration in order to prevent blockage or fouling of the hollow fiber membranes. However, scanning electron microscopy and particle size analysis of enzyme hydrolysates showed that enzyme treatment followed by filtration caused submicron particles to form and be trapped within the prefiltration media, which in turn, retained about 80% of the bacteria. Filtering prior to enzyme treatment resulted in formation of a filter cake consisting of protein particles retained on the surface of the filter, while facilitating passage of the much smaller microorganisms through the filter, separating them from particulates. Subsequent enzyme treatment of the filtrate resulted in an extract that was microfiltered in less than an hour, while concentrating viable microorganisms in the extract by 500x. An inoculum of Salmonella enterica cells into turkey burger containing of 1-20 CFU/mL, consisting of spiked cells plus cells already present in the turkey burger sample, was rapidly brought to levels detectable by conventional PCR and BAX (R) PCR assays. The entire procedure from sample processing to detection of Salmonella enterica was achieved in less than 8 h. (c) 2017 American Institute of Chemical Engineers Biotechnol.