The use of a benign fast-growing cyanobacterial species to control microcystin synthesis from .

Introduction: (), one of the most prevalent blue-green algae in aquatic environments, produces microcystin by causing harmful algal blooms (HAB). This study investigated the combined effects of nutrients and cyanobacterial subpopulation competition on synthesizing microcystin-LR.

Method: In varied nitrogen and phosphorus concentrations, cyanobacterial coculture, and algicidal DCMU presence, the growth was monitored by optical density analysis or microscopic counting, and the microcystin production was analyzed using high-performance liquid chromatography-UV. Furthermore, growth and toxin production were predicted using MATLAB.

Results And Discussion: First, coculturing with a fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 () reduced biomass and microcystin production at 30oC. Under high nitrogen and low phosphorus conditions, is mostly effective, with up to 94.7% and 92.4% limitation of growth and toxin synthesis, respectively. Second, this biological strategy became less effective at 23oC, where grew slower. Third, photosynthesis inhibitor DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) hindered growth (at 0.1 mg/L) and microcystin production (at 0.02 mg/L). DCMU was also effective for controlling microcystin production in - cocultures. Based on experimental results, a multi-substrate, multi-species kinetic model was built to describe coculture growth and population interactions.

Conclusion: Future research should examine more complex models to further develop and refine to facilitate the derivation of more effective recommendations for health prevention programs, particularly for mothers and girls.