The Effect of Dissolved Nutrients and Inorganic Suspended Solids on the Survival of E. coli in Seawater
The effect of dissolved nutrients and inorganic suspended solids on E. coli inactivation has been examined in laboratory experiments. The work employed artificial seawater with dissolved glucose and peptone, laboratory processed suspended solids and chemostat steady state E. coli cultures to establish the effect of these parameters on the viability of an E. coli population. Initial E. coli concentration was 5 × 103 100ml−1, the temperatures 5 °C and 20°C, the suspended solids concentration range was 0 - 100mgl−1, glucose concentration l.0mgl −1, peptone concentration 9.0mgl−1, salinity range 27 - 32‰ and the experimental vessels were shielded from light. Previous work has shown that nutrient-free inorganic suspended solids, at low concentrations, markedly increased the survival of E. coli in seawater. The work presented here shows that the presence of dissolved nutrients greatly increased E. coli survival, in the absence of suspended solids. However at suspended solids concentrations of >5 - 12mgl−1survival time was greatly reduced; thereafter increasing suspended solids concentration in the range >12.5 - 100mgl−1, generally resulted in increasing survival times.