콜리형 세균 Plasmid의 영양단계 지표 활용에 관한 연구

Application of Coliform Bacterial Plasmid as a Trophic Indicator

This present study has been carried out to examine the correlation between the distribution of the coliform bacterial plasmids and the viability test against heavy metals in the upper stream of Han river(Gapyung; clean water) and the its basin (Anyang Cheon; polluted water). And the distribution of plasmids were examined to be used as trophic indicator for analysis between the clean and polluted waters. 1. A total of 110 isolates were analyzed for the presence of plasmids by means of the boiling method and agarose gel techniques. Plasmids were significantly more frequent in the strains which had been isolated from the clean water (14.3%). Also, there were much higher multiplicity of plasmids at the polluted water(41.0%), compared with the clean water (33.0%). By the comparision between molecular weight of bacterial plasmids in the clean water and those of polluted water, there were no significant differences of the clean water from the polluted water, to such extent as 30.0%, 28.6%, respectively, in frequency for occurrence of high molecular weight plasmids iver 35.8% Mdal. 2. Each isolate was carried out the resistance test for mercury(10-5M), nickel(10-3M) and arsenic (0.1%). At the polluted site, the survival ability of the plasmid-carrying straings(Hg, 31.0%l Ni, 5.7%; As, 65.7%) was higher than that of the non plasmid-carrying strains(Hg, 12.1%; Ni, 3.0%; As, 54.6%). This trend was more remarkable in the clean site (plasmid-carrying strains: 16.7%,-,-). As a result it is suggested that plasmids could be used as an indicator of a certain types of water pollution. In addition, heavy metals might have inflyenced, some extent, to the distribution of plasmids in the environment which has been surveyed in the present study.