Application Of Whole-cell FISH In Water Bloom Warning And Initial Study Of Decontamination With Three Freshwater Filamentous Cyanobacteria

In the present work, based on fluorescence in situ hybridization (FISH) technique, Microcystis aeruginosa, a main species of Microalgae on water bloom was studied. The FISH protocols for whole cell and nuclear were established to detect this kind of alga. The probe was designed by the software Oligo, according to ITS sequence of M. aeruginosa. And the 5'end of the probe was marked by FITC.Green fluorescence issued by cells of M. aeruginosa was observed through fluorescence microscopy. Three species of filamentous cyanobacteria in freshwater and a kind of large marine algae was selected for the control, the green fluorescence was not observed. The experimental results show that the probe designed for M. aeruginosa has a high degree of specificity, can be used for qualitative and quantitative analysis of M. aeruginosa in the natural waters, which will play a role in forecasting water bloom caused by outbreaks of microalgae. At the same time, this work carried out mixed culture research within three species of filamentous cyanobacteria in freshwater and M. aeruginosa. Based on detecting the changes of the growth of algae measured by wet weight, as well as the changes of main nutrients N, P content in medium, the mutual influence among M. aeruginosa and the three species of filamentous cyanobacteria in freshwater and a kind of large marine algae was studied. The results showed that mixed culture of filamentous algae and M. aeruginosa, the growth of M. aeruginosa was inhibited obviously. The growth of filamentous cyanobacteria in mixed culture group was higher than the single culture group, as well as the medium pH increased.