Abstract
With the exploration and development of the practical technology for prevention and control of harmful algae blooms (HABs), cyanobacterium Microcystis aeruginosa (M. aeruginosa) blooms have been an urgent problem in the area of water resources protection. Allelopathic algicides are regarded as potential natural resources to constrain HABs for their exclusive and efficient characteristics. Previously, the allelopathic effect of rice has received great attention, but most of them are focused on herbicides to inhibit barnyard grass. In the present study, the effect of algal cells treatment with different concentrations of the rice straw aqueous extract were tested. A continuous culture system was established and the results suggested that the doses of rice straw aqueous extract in the range from 4.0 to 10.0gL−1 observably suppressed the growth of algae cells in a concentration-dependent way. After 9 days of treatment, the algae cells' metabolic activity decayed and the largest inhibition rate could be up to 98%, almost no algae growth was observed. In the case of eliminate the interference of nutrient elements, these results confirmed that rice straw aqueous extract may act as an algistatic agent.
•The rice straw was chosen for inhibitory experiment on Microcystis aeruginosa.•A continuous culture system was designed for simulating a natural environment.•The material suppressed the growth of algae cells in a concentration-dependent way.•An inhibitory effect was observed in the continuous culture experiment.•We explored the mechanism and the possibility for practical application.