Algicidal activity of prodigiosin against harmful algae.

Prodigiosin (PG),a secondary metabolite (red pigment) produced by Serratia marcescens and other bacteria,possesses a lot of bioactivity. However,its algicidal effect was not researched in detail. The algicidal activity of prodigiosin against harmful algae,causing red tide and fresh water bloom,and its light decomposition were studied. The algicidal concentration of prodigiosin for completely killing harmful algae in 24 hours including Nitzschia closterium,Skeletonema costatum,Anabena flosaquae and Merismopedia spp. were 5.0 μg/mL. When 5.0 μg/mL prodigiosin was exposed under the light of 30000lx for 36 h,all prodigiosin was photodecomposed. The light sensistivity of prodigiosin will not bring secondary pollution to the natural environment.