The Pennsylvania State University at Erie, The Behrend College, Erie, Pennsylvania 16563, USA.
Biotechnol Bioeng. 1993 Jun 5;42(1):125-32. doi: 10.1002/bit.260420117.
Effect of tube diameter on steam-in-place sterilization of dead-ended tubes was studied by examining temperature profiles and rates of kill of Bacillus stearothermophilus spores. Time required for sterilization was determined for 9.4-cm-long tubes with various inside diameters from 0.4 to 1.7 cm. Sterilization time increased with decreasing tube diameter. Experimentally measured kill kinetics in 1.7-cm tubes were in agreement with those predicted if measured temperatures represented saturated steam. A 12-log spore reduction was achieved in 1.7-cm diameter vertical and horizontal tubes in less than 63 minutes. For smaller diameter tubes, entrapped air remained after 2 hours and rates of kill were very dependent on position within the tube, tube diameter, and tube orientation with respect to the gravitational vector. Times to achieve a 1-log drop in spore population in the smaller tubes were as much as 10 times greater than those expected if measured temperatures represented saturated steam. Sterilization was not achieved throughout the 0.4-cm tubes. Recommendations are made for including steam bleeders or using prevaccum cycles for these smaller diameter tubes.
研究了管直径对死端管原位蒸汽灭菌的影响，方法是检查芽孢杆菌嗜热脂肪芽孢杆菌孢子的温度曲线和杀灭率。对内径从 0.4 厘米到 1.7 厘米的各种 9.4 厘米长的管子进行了灭菌时间的测定。随着管直径的减小，灭菌时间增加。在 1.7 厘米的管子中测量到的杀菌动力学与如果测量的温度代表饱和蒸汽所预测的杀菌动力学一致。在不到 63 分钟的时间内，在 1.7 厘米直径的垂直和水平管中实现了 12 对数的孢子减少。对于较小直径的管子，在 2 小时后仍残留有空气，并且杀灭率非常依赖于管内的位置、管直径以及管相对于重力矢量的方向。在较小的管中，实现孢子群下降 1 对数所需的时间比如果测量的温度代表饱和蒸汽时预期的时间长 10 倍。在 0.4 厘米的管子中未达到完全灭菌。建议为这些较小直径的管子包括蒸汽放气口或使用预抽空循环。
