title: [Mechanisms of algal inhibition by rice straw extract].
abstract: An indoor experiment was conducted to investigate the inhibition effects and mechanisms of rice straw extracts to the harmful bloom-forming algae, Microcystis aeruginosa. It was found that there were algae inhibitory chemicals in rice straw. The inhabitation ratio of rice straw extract to Microcystis was 69.3% when stored at a low temperature of - 4 degrees C for 4 days with a concentration of 2.5 g/L. The algal inhibition depends on both chemicals and biological responses from decomposed rice straw extracts. Their relative contributions to the algal inhibition depended on decomposition pathway and time. Algal inhibitory chemicals played more important roles in anaerobic decomposed rice straw extracts than aerobic decomposed ones in the algal-inhibition process. For anaerobically decomposed straw extracts, if stored for 15 and 30 days with the concentration of 1.5 g/L, the inhabitation ratio of rice straw to Microcystis was 83% and 46% respectively. However, for aerobically decomposed straw extracts, the biologic mechanism was more important. The inhibition effects of biologic mechanism increased with the decomposition time. For aerobically decomposed straw extracts, if stored for 15 and 30 days with the concentration of 1.5 g/L, the inhabitation ratio of rice straw to Microcystis was 81% and 93% respectively.
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. fengjinghehe@163.com
authors.forename: Jing
authors.initials: J
authors.lastname: Feng
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhu
authors.forename: Wei-zhong
authors.initials: WZ
authors.lastname: Wu
authors.forename: Ke-jian
authors.initials: KJ
authors.lastname: Rui
authors.forename: Yan-bo
authors.initials: YB
authors.lastname: Li
mesh_terms: D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development; D005618:Fresh Water / Q000032:analysis; D046931:Microcystis / Q000187:drug effects* / Q000254:growth & development; D012275:Oryza / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018547:Plant Stems / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D010936:Plant Extracts