Isolation And Algae-lysing Characteristics Of The Algicidal Bacterium Against Heterosigma Akashiwo

The increased toxic dinoflagellate blooms have influenced the people's life and health, and it has become the serious problem in the whole world. Recently, algicidal bacteria have attracted wide attentions as possible agent for inhibiting algal blooms. The aim of this study was to isolate and identify algicidal bacteria against the dinoflagellate Heterosigma akashiwo, and to determine the algicidal activity and algicidal range. An algae-lysing bacterium strain F5-2 was isolated from Yandong Lake in Wuhan City, which has algicidal effects to H.akashiwo. F5-2 showed significant algicidal activities against H.akashiwo and three other dinoflagellates, including Scrippsiella trochoidea,Prorocentrum micans,Prorocentrum minimum, but showed no effects on Chattonella marina,Chaetoceros muelleri,Chrysophyta. On the basis of biochemical and chemotaxonomic characteristics, and analysis of 16SrDNA sequences, F5-2 belonged to the genera Pseudomonas aeruginosa. F5-2 was a Gram-negative bacteria, and it was assumed to lyse algae by secreting an extracellular polysaccharides algicidal substances or other algicidal substances. Taken together, our results suggest that F5-2 could be a candidate for controlling red tides.