Natural Microcosms Research Articles

The Use of Microcosms to Simulate Field Experiments to Determine the Effects of Herbicides on Aquatic Bacteria

Small (3.5 1) laboratory microcosms containing water, sediment and Elodea canadensis were treated with the herbicides diquat and terbutryne. After treatment total numbers of planktonic bacteria increased significantly by 3-11-fold and heterotroph counts also rose significantly, by 3-23-fold but the population increases of exoenzyme-producing bacteria (3-113-fold) were not always significant. As the plants stopped photosynthesizing and decomposed, pH and dissolved oxygen concentrations declined, whilst alkalinity and free CO2 concentrations increased. All these changes were very similar to results from analogous experiments in natural waters and microcosms are recommended as substitutes for field experiments with aquatic herbicides.

Molecular genetic and phenotypic alteration of Escherichia coli in natural water microcosms containing toxic chemicals

Molecular genetic and phenotypic alteration of Escherichia coli in natural water microcosms containing toxic chemicals