香根草对铜绿微囊藻的生长抑制及其成分分析

摘要

随着水体富营养化程度的加剧,藻类等大量繁殖, 在对水体造成破坏的同时, 藻类产生的藻毒素会使动物中毒或通过食物链传递,威胁人类的健康.为控制富营养化水体中蓝藻的数量, 减少水华的发生, 利用生态浮床技术,以浮床植物香根草为研究对象,通过在铜绿微囊藻培养中添加香根草种植水, 研究香根草对铜绿微囊藻的抑制效应.每 3 d 使用血球计数板计算藻细胞密度, 记录接种微囊藻的种植水和对照处理下的藻类数量;并用分光光度法测定培养液中铜绿微囊藻的叶绿素 a 含量, 使用固相萃取方法收集香根草种植水中的根系分泌物,经气质联用仪(GC-MS) 分析香根草种植水中的化学物质.结果表明: 以蒸馏水培养 5 d 收集获得的香根草种植水对铜绿微囊藻的生长有明显的抑制作用.与对照组相比, 香根草种植水中培养的铜绿微囊藻生长缓慢.其中培养 6 d 后,香根草种植水开始对铜绿微囊藻的生长产生抑制作用, 且抑制作用随时间的推移而增加,在与铜绿微囊藻共培养 21 d 后,抑制率达到 76％ .种植水中藻类叶绿素 a 含量为 447. 62 mg/L,对照组铜绿微囊藻叶绿素 a 含量则高达 3 592 mg/L,为试验组的 8 倍.香根草根系分泌物中有 24 种化合物, 其中己酸、 棕榈酸、硬脂酸等脂肪酸对铜绿微囊藻等藻类有抑制作用.2-羟基丙酸相对含量最高, 为 50. 71％;其次是棕榈酸, 相对含量为 23. 2％ .香根草种植水通过抑制铜绿微囊藻的光合作用,对铜绿微囊藻的生长产生抑制作用.%With the aggravation of eutrophication of water body, algae can be propagated in large amount. The toxin produced by algae will cause the animals to be poisoned or pass through the food chain,threatening the health of human beings. In order to control the number of the blue-green algae in eutrophic water,this experiment used ecological floating bed technology to study the inhibition effect of Vetiveria zizanioids on Microcystis aeruginosa by adding the water which planted V. zizanioids in the culture of M. aeruginosa. The cell density was calculated with the blood cell count board per 3 d, and the content of chlorophyll a of M. aeruginosa was measured by spectrophotometric method. The chemical substances in V. zizanioids were analyzed by GC-MS. The results showed that the growth of M. aeruginosa was significantly inhibited by the root secretions of V. zizanioids. The highest inhibitory rate (76％) could be reached within 21 days. The results showed that the chlorophyll a concentration of algae in the plant was 447. 62 mg/L,and the concentration of chlorophyll a in the control group was up to 3 592 mg/L, The ρ(Chla) of the controls could be as 8 times high as that of the experiments. The results of GC-MS analyses showed that there were 24 fatty acids in the root secretions of V. zizanioids. Those acids included hexanoic acid,palmitic acid,oleic acid and stearic acid,etc. The relative content of lactic acid was the highest(50. 71％) , followed by palmitic acid(23. 2％) . The V. zizanioids water can inhibit the growth of M. aeruginosa by inhibiting photosynthesis and growth quantity of M. aeruginosa.