AWWA QTC98220

Molecular methods which target nucleic acids enable us to characterize bacterial populations without cultivation procedures. Polymerase chain reaction (PCR) amplification has become the method of choice for analyzing bacterial population in water samples. In this study, two molecular approaches based on PCR amplification of nucleic acids extracted from filtered water concentrates were followed for bacteriological analysis of water: a broad spectrum approach consisting of a PCR-based rRNA analysis to determine microbial diversity in a groundwater sample, and a specific PCR assay to directly detect a target microorganism in water samples. Materials and methods for the molecular rRNA-based strategy include: water sample collection; bacteriological examination; genomic DNA extraction and purification; construction of bacterial small-subunit rDNA clone library; RFLP analysis; and, sequence analysis and nucleotide accession numbers. Materials and methods for the specific PCR assay include: water sample processing; amplification by nested-PCR; and, dot blot hybridization. Results and conclusions are discussed.