Gibson A M, Bratchell N, Roberts T A
J Appl Bacteriol. 1987 Jun;62(6):479-90. doi: 10.1111/j.1365-2672.1987.tb02680.x.
A selective medium was used to enumerate Clostridium botulinum growing in the presence of natural spoilage organisms in a model cured pork slurry. The growth responses of a mixed spore inoculum of six strains of Cl. botulinum type A were studied at 15 degrees, 20 degrees and 27 degrees C with 1.5, 2.5, 3.5 or 4.5% (w/v) salt added (aw range 0.961-0.990). Gompertz and logistic curves, which have a sigmoid shape, were fitted to the data and lag times, growth rates, generation times and time to maximum growth rates were derived. Variation in germination rates of the spores occasionally gave a falsely extended lag time resulting in an exceptionally high estimate for growth rate. Products containing 4.5% (w/v) NaCl would be capable of supporting growth of proteolytic strains of Cl. botulinum, even at 15 degrees C, although the lag period would be extended. In products where absence of Cl. botulinum cannot be assured additional preservative measures are essential. The information obtained provides a framework to investigate the effects of a wider range of additives or variables on the growth responses of Cl. botulinum.
使用一种选择性培养基对在模拟腌制猪肉泥中与天然腐败菌共存时生长的肉毒梭菌进行计数。研究了在添加1.5%、2.5%、3.5%或4.5%（w/v）盐（水活度范围为0.961 - 0.990）的情况下，六株A型肉毒梭菌混合孢子接种物在15℃、20℃和27℃下的生长反应。将具有S形的冈珀茨曲线和逻辑曲线拟合到数据中，并得出延迟期、生长速率、代时和达到最大生长速率的时间。孢子萌发率的变化偶尔会导致错误延长的延迟期，从而使生长速率的估计值异常高。含有4.5%（w/v）NaCl的产品即使在15℃时也能够支持蛋白水解型肉毒梭菌的生长，尽管延迟期会延长。在不能确保不存在肉毒梭菌的产品中，额外的防腐措施至关重要。所获得的信息提供了一个框架，用于研究更广泛的添加剂或变量对肉毒梭菌生长反应的影响。
