Preliminary Study On Inhibitory Of Three Algae-lyzing Bateria To Phaeocytstis Globosa And Prorocentrμm Dentatum

Red tide happens frequently in recent years and it becomes one of the largest natural disasters in the world. Therefore, the management and governance of red tide are becoming more and more important. In previous researches, bacteria were applied to control red tides. Phaeocytstis globosa and Prorocentrum dentatum are two causative species of red tides which are often seen in South China Sea and East China Sea, respectively. The main purpose of this study was focused on the biological-control methods of these two causative species.In this work, a few bacteria were separated from water samples which were collected in Zhuhai Sea. Three bacteria had pronounced algae-lytic ability, i. e. T01, T02, and T03. The preliminary studies of identification and properties of the three bacteria were carried out afterward.Three bacteria significantly inhibited the growth of Phaeocytstis at its early stage. The removal efficiency achieved to 90ï¼…after algae-bacteria had cultured together for three days. The same percentage was gained after 8 days and 9 days when Phaeocytstis and Perorocentrum at their index growth stages, respectively. The results showed that the T01 had better algae-lytic ability than T02 and T03. Bacteria T01 and T02 were more effective to Phaeocytstis than Perorocentrum. However, for T03, there was no significant difference to two kinds of algae.After algae-lyzing, the pigment composition of two kinds of algae did not change obviously, while the content of chlorophyll a and the density of algae decreased. The content of glycose altered but the composition did not change significantly. The Phaeocytstis was not easy to congregate after adding bacteria. From the fluorescence intensity by flow cytometer, the larger bulk algae grew more thrived. In other words, the algae-lyzing bacteria had better inhibition to small bulk algae.