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目的对通过高压热水冲淋前后肉牛胴体表面的极端微生物数量及种类的变化规律进行研究。方法细菌菌落计数,并从分离的极端微生物中随机挑出8株厌氧菌和7株嗜冷菌,利用16S r DNA扩增、测序及生化试剂盒鉴定这些微生物的种属特征。结果冲淋前后的肉牛胴体表面细菌菌落总数从106CFU/cm2降低至500 CFU/cm2,同时冲淋前后的肉牛胴体厌氧细菌总数从2×102CFU/g下降至400 CFU/g,嗜冷细菌总数从3×104CFU/g下降至3×102CFU/g。极端微生物主要属于厌氧芽胞杆菌属Bacillus sp.、埃希菌属、肠杆菌属Enterobacter sp.、库特菌属Kurthia sp.、沙雷菌属Serratia sp.、假单胞菌属Pseudomonas sp.等6个属。结论高压热水冲淋可以很好的控制肉牛胴体表面细菌菌落总数,但对于厌氧、嗜冷等极端微生物的减菌效果不是很理想。
Objective To study the changes of the number and species of extremophiles on the carcass surface of beef cattle before and after high pressure hot water showering. Methods Bacterial colonies were counted. Eight anaerobic bacteria and seven psychrophilic bacteria were randomly selected from the isolated extremophiles. The species characteristics of these microorganisms were identified by 16S rDNA amplification, sequencing and biochemical kit. Results The total number of bacterial colonies on the surface of beef carcass before and after showering decreased from 106CFU / cm2 to 500 CFU / cm2. The total number of anaerobe bacteria in beef carcass before and after showering decreased from 2 × 102CFU / g to 400 CFU / g, From 3 × 10 4 CFU / g to 3 × 10 2 CFU / g. The extremophiles belong to the genus Bacillus sp., Escherichia, enterobacter sp., Kurthia sp., Serratia sp., Pseudomonas sp. 6 genera. Conclusion High-pressure hot water shower can control the total number of bacterial colonies on the surface of beef carcass, but it is not ideal for reducing bacteriostasis of anaerobic, psychrophilic and other extreme microorganisms.