Algicidal effects and denitrification activities of Acinetobacter sp. J25 against Microcystis aeruginosa

Harmful algal blooms (HABs) could be deemed hazardous materials in aquatic environment. Microcystis aeruginosa is a toxic HAB causing alga, which causes serious economic losses and health problems. In this study, a strain J25 with the high algicidal activity isolated from an eutrophic Qu Jiang Lake, was identified as Acinetobacter sp. based on its morphological features and phylogenetic analysis by sequencing of 16S rDNA. Its algae-lysing characteristics on M. aeruginosa, was tested under the different conditions. The results showed that the strain J25 had good tolerance of acid and alkali, and full illumination played a positive role in the algae removal. Furthermore, this was the first report about the relationship between algicidal and denitrification activities. The maximum denitrification rate (1.62 mg NO₃^--N L^-1 h^-1) was observed within 6 days at 15% of inoculum.