水稻(Dryza sativa L．)秸秆浸提液对铜绿微囊藻(Microcysti aeruginosa)的抑制作用

The inhibition of aqueous extract from Oryza sativa straw on growth of Microcystis aeruginosa

用刚收割的水稻(Oryza sativa L．)秸秆浸提液代替水配制培养基培养铜绿微囊藻(Microcystic aeruginosa),追踪测定微囊藻的生物量、叶绿素a含量、光合速率、呼吸速率、膜透性、超氧物歧化酶(SOD)活性、光合膜自发荧光强度等相关生理生化指标的变化,研究水稻秸秆浸液对铜绿微囊藻的抑制作用．结果表明,质量比≥1/100(水稻秸秆/水)的水稻秸秆浸提液对微囊藻的生长有明显的抑制作用,表现如下:藻细胞生物量在实验过程中逐日降低,藻细胞叶绿素a含量和光合速率急剧下降,呼吸速率和超氧物歧化酶(SOD)活性呈先升高后下降的趋势,膜透性迅速升高,细胞光合膜自发荧光强度显著衰减．用不同的有机溶剂对该浸提液进行萃取,浓缩后用滤纸片法在固体培养基上做抑藻实验,乙醚和乙酸乙酯萃取液能明显看到抑藻圈,证实其中含有抑制物质．

Mivrocystic aeruginosa was co-cultivated with aqueous extract from fresh reaped Oryza sativa L. straw and the inhibiting effect of this aqueous extract on M. aeruginosa was studied in this paper. Results indicated that the growth of M. aeruginosa was obviously inhibited when the rate of quality was over 1/ 100 （rice straw / water）. Chlorophyll a content, photosynthetic rate and the intensity of spontaneous fluorescence decreased continuously as the treatment went on ; respiratory rate and SOD activity decreased evidently at the first 3 days of treatment and then increased; membrane penetrability increased at the first 5 days of treatment and then decreased slowly. Some substances were extracted from the aqueous extract by different organic solvents （ether, ethyl acetate and petroleum ether 30- 60℃ ）, respectively. Inhibiting effect could be observed with filtering paper methods on solid medium when the substances were extracted by ether, ethyl acetate. This suggested that some inhibitive factors might exist in these substances.