Quantitative Erfassung von Bakterien und deren spezifische Aktivität in komplexen Habitaten mittels Fluoreszenzmikroskopie und digitaler Bildverarbeitung

摘要

The aim of this PhD thesis was to develop a procedure for both the determination of the concentration of bacteria and their specific activity in complex habitats. Because of the deficiency of common used techniques for the determination of total counts, the total sytox count was developed. The new procedure consists of the colouring of the DNA of fixed cells with the fluorescence dye Sytox Green. Counting of the coloured cells was carried out by means of epifluorescence microscopy in combination with an adapted digital image analyzing system. The recovery of spiked cells to soil samples reached 80 Þ 40%. In combination with Fluorescence in situ Hybridization (FISH), the specific activity of cells parallel to the total counts could be determined. The feasibility of FISH for the determination of specific activities was shown. For the better performance of the total sytox count and FISH, a new staining-reactor, the FinStR, was developed and patented. In batch cultures, the total sytox count was applied for total counts in two model systems (A: Pseudomonas putida DSM-Nr.8368, Phenanthrene and Montmorillonit; B: Ralstonia eutropha JMP134-1, 2,4-Dichlorophenol and Dodecltrimethylammonium+ modified Mont-morillonit). In both model systems, slight changes in bacterial concentrations were successfully determined in the presence of clay minerals.