污染环境中细菌质粒的研究

STUDY ON BACTERIAL PLASMIDS IN POLLUTED ENVIRONMENT

Investigation was made on species of aerobic hetertrophic bacteria, along with the presence of their plasmid DNA, from various sites where are clean or polluted by petrolium alkane,pesticide or mercury.Semicontinuous mixed culture in chemostat was carried out for the study on variation in percentage of bacteria containing plasmids. The results showed that in the chemostat niche 29 of 76 initial strains were found with plasmids. and all of 6 strains detected after 6 monthes running contained plasmids. The percentage of those with plasmids of the 470 strains isolated from various sites was different. 49% for those from artificial oil plluted sites; 41% for those from pesticide (e.g., pentachlorophenol) polluted sites; and 11.3% for the control. The incidence of plasmid in mercury resistant bacteria was 62%.Of 102 strains carrying plasmid,78% could degrade petroleum alkane to different extents; 74.6% were Gram-negative; and 31.6% were Pscudomonas-likes.