Effect of Phyto- and Zooplankton on the Growth of Marine Bacteria in Filtered Seawater

Abstract

Living phyto- or zooplankton was isolated aseptically from natural seawater and incubated in seawater, enriched with small amounts of nitrogen and phosphorus sources under controlled conditions. The effect of the added plankton on the growth of heterotrophic bacteria and Vibro sp. in particular, were assessed. The overall results showed that generally phytoplankton specifically suppressed the growth of Vibrio sp., while zooplankton enhanced it. These effects were clear in samples incubated for 12 or 24 hours. The inhibitory effect of the phytoplankton became less remarkable after a longer period of incubation.