• The Korean Journal of Ecology
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• v.28 no.3
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• pp.129-134
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• 2005

The monthly variations of physico-chemical and microbiological water quality were investigate in the artificial Lake Geumgang near estuary barrage. Sixty heterotrophic bacteria were isolated and identified by amplification and sequencing of 16S rDNA. Water temperature, pH, and inorganic nutrients($NH_4$-N, $NO_2$-N, $NO_3$-N, $PO_4$-P) were measured. Concentrations of DO, BOD, and inorganic nutrients were lower than in the middle-stream of Geum river The population densities of heterotrophic bacteria and total coliforms varied from $4.1{\pm}1.0\times10^2$ to $6.7{\pm}1.1{\times}10^3\;cfu\;ml^{-1}$, and 0 to $2.3{\pm}0.6{\times}10^2\;cfu\;ml^{-1}$, respectively. Among the measured numbers of physiological groups of bacteria, cellulolytic bacteria showed higher population densities than those of other physiological groups. Bacterial community structure was analysed based on 16S rDNA partial sequencing. Among 60 isolates, dominant genus was Pseudomones (20 strains).

• The Korean Journal of Ecology
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• v.27 no.5
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• pp.283-289
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• 2004

This study was conducted to evaluate the annual population variation and identification of antibiotic-resistant bacteria in the lower artificial Lake Geumgang from January to December, 2002. Samples were taken from the surface waters at 3 stations near the estuarine barrage. The results were as follows; the population densities of heterotrophic bacteria varied from 4.1±1.0×10² to 6.7±1.1×10³ cfu ml/sup -1/ during the investigation periods. The population densities of antibiotic-resistant bacteria ranged from 1.5±0.7×10 to 4.3±0.3×10³ cfu ml/sup -1/ for ampicillin; from 0 to 6.4±0.4× 10² cfu ml/sup -1/ for chloramphenicol; from 0 to 2.8±0.3×10³ cfu ml/sup -1/ for gentamicin; from 0 to 4.5±1.0×10³ cfu ml/sup -1/ for kanamycin; and from 1.0±0.4 × 10 to 2.3±0.5×10³ cfu ml/sup -1/ for streptomycin, respectively. Of the sixty isolates, 90% were Gram negative. Dominant genera by 16S rDNA analysis were identified Aeromonas spp. (14 strains), Bacillus spp. (6 strains), Enterobacter spp. (4 strains), and Stenotrophomonas spp. (6 strains). These strains were clustered into 12 groups based on relatedness by average linkage method. Of the 60 isolates, 85% had the resistance to ampicilin and 32% were shown resistance to more than 2 kinds of antibiotics.