Atmospheric analysis and redox potentials of culture media in the GasPak System
Atmospheric analysis and redox potentials of culture media in the GasPak System
复制标题
GasPak 系统中培养基的大气分析和氧化还原电位
DOI：
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发表时间：
1980
影响因子：
9.4
通讯作者：
G. Evans
中科院分区：
文献类型：
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作者：
W. Seip;G. Evans
在GasPak 100厌氧系统（BBL Microbiology Systems，科基斯维尔，马里兰州）中，在环境温度（20 - 25 ℃）下，监测氧气和二氧化碳浓度、内部大气压力、催化剂温度和水冷凝物出现的时间，持续不同的时间间隔。同时，还测定了系统中各种平板培养基的氧化还原电位（Eh）。氧浓度在100分钟内降低至小于0.4%。介质的Eh（针对氢离子校正）在60至100分钟内达到-100 mV，二氧化碳浓度在60分钟内增加至4%至7%，这取决于存在的介质板数。冷凝液出现一般在10和15分钟之间，和盖子的温度达到最大值之间的20和40分钟。冷凝时间和盖子温度的增加是一个正常运作的GasPak系统的重要早期指标。由于氢气和二氧化碳气体的受控释放以及氢气和氧气反应生成水，产生了特征压力-真空-压力曲线。厌氧条件在亚甲蓝厌氧指示剂脱色之前就已经达到，这需要在20至25 ℃下超过6小时。此时，广口瓶中培养基的Eh远低于-200 mV。由于指示剂在35 ℃下5小时内减少，因此罐中介质的Eh也预计在较高温度下更快地降低。
Oxygen and carbon dioxide concentrations, internal atmospheric pressure, catalyst temperature, and time of appearance of water condensate were monitored for various time intervals at ambient (20 to 25 degrees C) temperature in a GasPak 100 Anaerobic System (BBL Microbiology Systems, Cockeysville, Md). Simultaneously, the redox potential (Eh) of various plated culture media in the system was also measured. The oxygen concentration was reduced to less than 0.4% in 100 min. The Eh of the media, corrected for hydrogen ion, reached -100 mV within 60 to 100 min, and the carbon dioxide concentration increased to between 4 and 7% in 60 min, depending on the number of plates of media present. Condensate appeared generally between 10 and 15 min, and the temperature of the lid reached a maximum between 20 and 40 min. Condensate time and lid temperature increase are important early indicators of a correctly functioning GasPak System. A characteristic pressure-vacuum-pressure profile is produced as a result of controlled release of hydrogen and carbon dioxide gases and the reaction of hydrogen and oxygen to produce water. Anaerobic conditions were achieved well before the methylene blue anaerobic indicator became decolorized, which required more than 6 h at 20 to 25 degrees C. At this time the Eh of media in the jar was well below -200 mV. Since the indicator is reduced within 5 h at 35 degrees C, the Eh of media in the jar would also be expected to decrease more rapidly at the higher temperature.