The effect of carbon dioxide on the germination and prolification of Clostridium botulinum

研究了CO2在5℃等低温条件下对肉毒梭菌萌发的影响。在研究CO2对5℃条件下芽孢萌发的影响过程中，发现该菌孢子在短时间CO2环境下失去热稳定性。研究了低温条件下CO2气氛对肉毒杆菌芽孢在琼脂表面和几种食物上热失活的影响。结果表明，在低温（5℃）CO2气氛下培养芽孢，经60℃、30min轻度热处理后，芽孢的活孢数明显减少。此外，为了使食物的味道更好而进行减热灭菌处理的食物，有被肉毒杆菌污染的风险。在包装过程中，很难防止高耐热性分数形成物污染这些产品。因此，本研究还旨在评估A型和b型肉毒杆菌在无菌煮米饭中的风险。此外，通过扩增肉毒杆菌神经毒素E型（BONT/E）基因280 bp的序列，建立了一种快速定量PCR （TaqMan assay）方法，对E型肉毒杆菌进行定量检测。该方法利用内部荧光探针的水解，利用abi PrismTM 7700序列检测系统（SDS）实时监测PCR过程中荧光强度的增加，可以对肉毒杆菌E型毒素基因进行准确、可重复的定量分析。

The effect of CO2 on the germination of Clostriiudium botulinum under cold emperature such as 5℃ was studied. During the course of investigations into the effect of CO2 on the germination at 5℃, it was observed that spores of this organism lose heat stability when the spores were placed under CO2 atmospheres for short period of time. This investigation was undertaken to determine the effect of CO2 atmosphere on the heat inactivation of spore of C. botulinum on an agar surface and several foods at cold temperatures. It was demonstrated that the number of viable spore decreases significantly by mild heat treatment (60℃, 30min) when the sprores were incubated under CO2 atmosphere under cold temperatues (5℃). Also, in foods treated with reduced heat sterilization to make the taste much better, there is a risk of contamination of C. botulinum. It is difficult to prevent from preventing contamination of high heat tolerant score formers into these products during packaging. Thus, this study also aimed to assess risks in aseptic boiled rice with C.botulinum type A and B. Moreover, A rapid quantitative PCR assay (TaqMan assay) which quantifies C. botulinum type E by amplifying a 280-bp sequence from the botulinum neurotoxin type E (BONT/E)gene is developed. With this method, which uses the hydrolysis of an internal fluoregenic probe and monitors in real-time the increase in the intensity of fluorescence during PCR by using theABI PrismTM 7700 Sequence Detection System (SDS), it was possible to perform accurate and reproducible quantification of the C.botulinumtype E toxin gene.