Rajkovic Andreja, Uyttendaele Mieke, Ombregt Sylvie-Anne, Jaaskelainen Elina, Salkinoja-Salonen Mirja, Debevere Johan
Laboratory for Food Microbiology and Food Preservation, Department for Food Safety and Food Quality, Faculty of Bioengineering Sciences, Ghent University, Belgium.
J Food Prot. 2006 Apr;69(4):847-52. doi: 10.4315/0362-028x-69.4.847.
Potato puree and penne pasta were inoculated with cereulide producing B. cereus 5964a and B. cereus NS117. Static incubation at 28 degrees C proved these two foods to be a better substrate for higher cereulide production (4,080 ng/g in puree and 3,200 ng/g in penne were produced by B. cereus 5964a during 48 h of incubation) compared with boiled rice (2,000 ng/g). This difference occurred despite B. cereus counts of more than 10(8) CFU/g in all three products. Aeration of cultures had a negative effect on cereulide production, causing concentrations more than 10-fold lower than in some statically incubated samples. Cereulide production remained undetectable in shaken milk, whereas it reached 1,140 ng/ml in statically incubated milk. At 12 and 22 degrees C, presence of background flora was also a determinative factor. A total B. cereus count of more than 106 CFU/ml did not necessarily lead to uniform cereulide production and was also dependent on the B. cereus strain involved. In this study, we confirm that a number of factors play a crucial role in the determination of the extent to which, if at all, cereulide will be produced. Among those, type of the food, temperature, pH, and whether additional aeration (via incubation on an orbital shaker) is induced had an important role. An important effect was also induced by the cereulide-producing strain involved.
将蜡样芽胞杆菌5964a和蜡样芽胞杆菌NS117接种到土豆泥和意大利面中，这两种菌可产生蜡样芽胞杆菌毒素。在28℃下静态培养证明，与米饭（2000 ng/g）相比，这两种食物是蜡样芽胞杆菌毒素产生量更高的更好底物（蜡样芽胞杆菌5964a在48小时培养过程中，土豆泥中产生4080 ng/g，意大利面中产生3200 ng/g）。尽管所有三种产品中的蜡样芽胞杆菌计数均超过10⁸ CFU/g，但仍存在这种差异。培养物通气对蜡样芽胞杆菌毒素的产生有负面影响，导致其浓度比一些静态培养样品低10倍以上。在振荡培养的牛奶中未检测到蜡样芽胞杆菌毒素的产生，而在静态培养的牛奶中其含量达到1140 ng/ml。在12℃和22℃时，背景菌群的存在也是一个决定性因素。蜡样芽胞杆菌总数超过10⁶ CFU/ml并不一定会导致蜡样芽胞杆菌毒素的均匀产生，这也取决于所涉及的蜡样芽胞杆菌菌株。在本研究中，我们证实许多因素在决定蜡样芽胞杆菌毒素是否产生以及产生程度方面起着关键作用。其中，食物类型、温度、pH值以及是否诱导额外通气（通过在振荡培养箱中培养）起着重要作用。所涉及的产生蜡样芽胞杆菌毒素的菌株也产生了重要影响。
