Stability of manipulated plasmid DNA in aquatic environments

Very little is known about the stability, behavior, and probability of perpetuation of genetically engineered DNA within a microbial community. The prevalence of genetically engineered microorganisms (and hence their DNA) in the environment as a result of deliberate or accidental release has been an increasingly controversial issue during the past few years. In the present study genetically manipulated plasmid DNA was seeded into different types of waters to determine its fate over time in the presence of naturally occurring bacterial populations. The seeded DNA was rapidly degraded in surface and marine waters. Up to 10 μg/mL was degraded in a few hours. The DNA was not degraded in water that had no detectable DNAse-producing microflora. No uptake of the DNA by the resident microflora was observed even where the DNA remained undegraded up to 7 days. We can thus extrapolate that, in some aquatic environments, the genetically engineered DNA will be degraded in a very short time and therefore the concerns of uptake of novel genes by the resident microflora may be overstated.