稻草浸泡液对藻类抑制作用机制

Mechanisms of Algal Inhibition by Rice Straw Extract

室内研究了不同降解方式和降解时间的稻草浸泡液对铜绿微囊藻生长的抑制效果及其抑藻机制.结果表明,稻草本身存在抑藻活性物质,低温浸泡4 d的无菌稻草液在2.5 g/L投加量下,对微囊藻的抑制作用达到了69.3%.在稻草浸泡液抑藻过程中,稻草产生的化学物质作用和生物作用同时存在,其相对大小取决于稻草的降解方式和降解时间.对于厌氧降解浸泡液而言,主要通过化学物质的作用抑藻,其抑藻效果随稻草厌氧降解时间的延长明显减弱,如厌氧浸泡15 d和30 d的稻草液在1.5 g/L浓度下其抑制率分别为83%和46%;好氧降解浸泡液主要通过生物作用抑藻.其抑藻效果随稻草好氧降解时间的延长而增强,如1.5 g/L投加量下,15和30 d好氧降解带生物相的稻草浸泡液对微囊藻的抑制率分别为81%和93%.

An indoor experiment was conducted to investigate the inhibition effects and mechanisms of rice straw extracts to the harmful bloomforming 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℃ 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.