[Survival capacity of genetically altered Escherichia coli strains. 2. Survival of pure cultures in different water and soil matrices].
The survival of two genetically engineered E. coli strains (L+, CAG+) compared to that of 4 control strains (N0, K12, L-, CAG-), was investigated in drinking water, surface water, sewage and soil under different conditions. Both genetically manipulated strains are able to produce Prourokinase, an anticoagulant. It was found, that all strains died off inspite of high inoculated bacterial densities. In drinking water, no bacteria could be recultivated immediately following inoculation. Upon inoculation in surface water, the genetically manipulated strains L+ and CAG+ were more sensitive than the other strains. The same was found for sewage under aerobic conditions, whereby, the control strains N0 and K12 as well as the wild-strains of the genetically manipulated organisms, L- and CAG- survived the whole experimental period and kept their numbers at a level between 100 and 1000 CFU/ml. Under anaerobic conditions, a die-off of all tested strains was similarly registered with time. The influence of the autochthonous microflora of sewage water could be documented in that, under these conditions, all test strains survived the whole experimental period of 31 days with the exception of the genetically manipulated strain CAG+. In soil experiments, it was found that the humus-rich garden soil was more effective in eliminating the E. coli strains than sand. The antagonistic effect of the autochthonous soil microflora was only clearly seen in experiments with garden soil. However, these results did not meet the expectations for the two CAG strains, for which a longer survival period had been previously established for in nutrient rich soil. In contrast to the E. coli control strains N0 and K12, the two L strains and the CAG+ strain survived the whole test period of 36 days. It can be concluded that under these simulated environmental conditions, all tested strains of E. coli die off more or less in a short period of time following inoculation with the autochthonous microflora of environmental samples.
Dott
W
W
Technischen Universität Berlin.
Khoury
N
N
Ankel-Fuchs
D
D
Henninger
W
W
Kämpfer
P
P
D000332:Aerobiosis; D000693:Anaerobiosis; D001604:Berlin; D015169:Colony Count, Microbial; D004792:Enzyme Precursors / Q000096:biosynthesis; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D005618:Fresh Water; D005818:Genetic Engineering; D012722:Sewage; D012988:Soil Microbiology; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis; D014871:Water Microbiology; D014881:Water Supply
D004792:Enzyme Precursors; D012722:Sewage; D014568:Urokinase-Type Plasminogen Activator
Uberlebensfähigkeit von genetisch veränderten Escherichia coli-Stämmen. 2. Mitteilung: Uberleben von Reinkulturen in verschiedenen Wasser- und Bodenmatrices.