Bissonnette G K, Jezeski J J, McFeters G A, Stuart D G
Appl Microbiol. 1975 Feb;29(2):186-94. doi: 10.1128/am.29.2.186-194.1975.
The problems associated with recovery of pure cultures of Escherichia coli and Streptococcus faecalis from stream environments were examined utilizing membrane filter chambers. It was observed that upon exposure to the aquatic environment a significant proportion of cells lost their ability to produce colonies on a selective medium, yet retained this capability on a nutritionally rich, nonselective medium. Discrepancies in colony-forming units between nonselective and selective media indicated that a substantial portion of bacterial cells may become physiologically injured due to the environmental stress imposed by the aquatic environment. The extent of injury was observed to vary considerably among the eight different stream environments, since the amount of injury was not uniform for all types of water environments examined. It was observed that the injury acquired by a population of E. coli, during exposure to the aquatic environment, could be rapidly repaired in a nutritionally rich, nonselective medium. As the injured population of cells was exposed to the rich, nonselective broth, increasing proportions of cells were able to repair themselves such that they became insensitive to inhibitory agents in selective media.
利用膜滤室研究了从溪流环境中分离大肠杆菌和粪链球菌纯培养物时遇到的问题。观察到，暴露于水生环境后，相当一部分细胞失去了在选择性培养基上形成菌落的能力，但在营养丰富的非选择性培养基上仍保留此能力。非选择性培养基和选择性培养基上菌落形成单位的差异表明，由于水生环境施加的环境压力，相当一部分细菌细胞可能受到生理损伤。在所研究的八个不同溪流环境中，损伤程度差异很大，因为在所检查的所有类型水环境中，损伤程度并不一致。观察到，大肠杆菌群体在暴露于水生环境期间所受的损伤，在营养丰富的非选择性培养基中可迅速修复。随着受损伤细胞群体暴露于丰富的非选择性肉汤中，越来越多的细胞能够自我修复，从而对选择性培养基中的抑制剂不再敏感。
