DETECTION OF SHIFTS IN MICROBIAL COMMUNITY STRUCTURE AND DIVERSITY INSOIL CAUSED BY COPPER CONTAMINATION USING AMPLIFIED RIBOSOMAL DNA RESTRICTION ANALYSIS

Amplified ribosomal DNA restriction analysis (ARDRA) was used for asse ssing the effect of copper contamination on the microbial community in soil. ARDRA is a DNA fingerprinting technique based on PCR amplificat ion of 16S ribosomal DNA using primers for conserved regions, followed by restriction enzyme digestions and agarose gel electrophoresis. Thi s results in distinguishable fingerprints for different bacterial spec ies. Microbial community structure in soil was investigated by studyin g ARDRA patterns of the whole community, and by comparing ARDRA patter ns of cloned 16S RNA gene sequences from soil and isolates obtained fr om soil by cultivation. Distinct differences in microbial community st ructure and a lower diversity were found in a soil contaminated with c opper compared with non-contaminated soil. Diversity of ARDRA patterns from the clones was higher than that from isolates, supporting the ge neral idea that the culturable population represents only a part of th e total (amplifiable) population in soil. To compare microbial communi ties from various soils a method is described for the construction of a dendrogram representing the relatedness of the populations. ARDRA ap pears to be suitable for analysing microbial communities in soil and g ives interesting information with respect to microbial ecology.