Persistence of Virus and Bacteria in Seawater

At a temperature of 38–40° F bacterial survivals (Escherichia coli) were significantly enhanced in seawater deliberately polluted with small concentrations of organic materials (25–500 ppm) including peptone, heart infusion, casamino acid, yeast extract, trypticase soy, and human feces. In a warmer environmental temperature the survival enhancing property of these substances became growth promoting resulting in a 40-fold population increase followed with a marked increase in microbial persistence lasting at least 18 weeks. These substances were also capable of stabilizing cell and colony morphology. The same phenomenon was not observed in parallel experiments with Echo 6 virus. In this instance, cold temperature per se appeared more effective in enhancing survival time. Inactivation rate was gradual and the virus persisted for 14 weeks at 38–40° F, contrasted sharply with an 8-day persistence at an environmental temperature of 72° F.