Plasmid transfer to indigenous marine bacterial populations by natural transformation

• Published in: BACTERIAL GENETICS AND ECOLOGY Vol. 15; no. 1‐2; pp. 127 - 135
• Main Authors: Frischer, Marc E., Stewart, Gregory J., Paul, John H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.1994; Blackwell
• Subjects: Animal, plant and microbial ecology; Bacteriology; Biological and medical sciences; Biotechnology; Environment and pollution; Fundamental and applied biological sciences. Psychology; Genetically engineered organisms behavior (microorganisms, plants, animals); Genetics; Industrial applications and implications. Economical aspects; Marine; Marine bacteria; Microbial ecology; Microbiology; Natural transformation; Plasmid; Various environments (extraatmospheric space, air, water); Pseudomonadales; Recombinant microorganism; Brackish water environment; Genetic transformation; Escherichia coli; Transforming DNA; Pseudomonas; Genetic transfer; Marine environment; Plasmid; Aquatic environment; Bacteria; Pseudomonadaceae; Vibrionaceae; Enterobacteriaceae; Vibrio
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.1994.tb00237.x

Horizontal gene transfer among microbial populations has been assumed to occur in the environment, yet direct observations of this phenomenon are rare or limited to observations where the mechanism(s) could not be explicitly determined. Here we demonstrate the transfer of exogenous plasmid DNA to members of indigenous marine bacterial populations by natural transformation, the first report of this process for any natural microbial community. Ten percent of marine bacterial isolates examined were transformed by plasmid DNA while 14% were transformed by chromosomal DNA. Transformation of mixed marine microbial assemblages was observed in 5 of 14 experiments. In every case, acquisition of the plasmid by members of the indigenous flora was accompanied by modification (probably from genetic rearrangement or methylation) that altered its restriction enzyme digestion pattern. Estimation of transformation rates in estuarine environments based upon the distribution of competency and transformation frequencies in isolates and mixed populations ranged from 5 × 10−4 to 1.5 transformants/1 day. Extrapolation of these rates to ecosystem scales suggests that natural transformation may be an important mechanism for plasmid transfer among marine bacterial communities.