Detection of micro-organisms in soil after in situ hybridization with rRNA-targeted, fluorescently labelled oligonucleotides

The possibility of utilizing fluorescently labelled oligonucleotides targeted against rRNA for the in situ detection of soil microorganisms was assessed. Initial experiments were carried out to determine if the procedure could detect, with minimal background activity, inoculated samples of Pseudomonas aeruginosa. The results showed minimal background activity due to organic matter, although the optimal bacterial recovery was not achieved. Species-specific probes could detect artificially spiked soil samples, however, the method was not effective in monitoring natural bacterial soil populations.