大型海藻羊栖菜对新月筒柱藻生长抑制作用研究

研究了羊栖菜藻体、干粉及乙醇提取物对新月筒柱藻生长的影响。结果显示:羊栖菜藻体、干粉和乙醇提取物皆可明显抑制新月筒柱藻的生长,羊栖菜粉末及乙醇提取物对新月筒柱藻的生长的抑制作用表现出较强的浓度-效应关系。72 h时,新月筒柱藻生长抑制率与羊栖菜干粉初始浓度间的关系可表达为y=-0.3801x2+1.1636x,新月筒柱藻生长抑制率与羊栖菜乙醇提取物初始浓度间的关系可表达为y=-0.1445x2+1.4279x。羊栖菜粉末浓度达到1.6 g/L时,新月筒柱藻在3 d内全部死亡;乙醇提取物浓度达0.8 g/L时,藻细胞在2 d内全部死亡。由于乙醇提取物溶液的浓度是以提取前干粉质量表示,因此同等质量的羊栖菜粉末经过乙醇提取后其对新月筒柱藻生长的抑制作用明显高于未经提取的羊栖菜粉末。在1.6 g/L的羊栖菜乙醇提取物作用下数小时后,新月筒柱藻细胞核破裂,并逐渐向两端分散,至24 h时,细胞膜模糊,界限不清,细胞严重萎缩并逐渐碎裂解体。研究亮点:本研究发现大型海藻羊栖菜对冷水性赤潮藻新月筒柱藻的生长具有克生作用,羊栖菜乙醇提取物能明显抑制新月筒柱藻的生长,并对其作用机理进行了初步探讨,为赤潮的生物防治提供理论基础,丰富了海洋化学生态学的研究内容。

Inhibition effect of macro-alga Sargassum fusiforme on micro-alga Cylindrotheca closterium

The effect of fresh thalli, dry powder and ethanol extracts from macroalga, Sargassum fusiforme, on the growth of a bloom forming microalga, Cylindrotheca closterium, was studied in co culture under controlled laboratory conditions. The results showed that the fresh thalli, dry powder and ethanol extracts exhibited strong inhibitory effect on the growth of C.closterium, and a concentration effect relationship was observed between the initial concentration of dry powder and the ethanol extracts and the growth inhibition of C.closterium. The relationship between the growth inhibition and the initial concentration of dry powder is y = -0.3801x² + 1.1636x, and it is y = -0.1445x² + 1.4279x between the growth inhibition and the initial concentration of ethanol extracts at 72 h. All the cells of C.closterium was dead in 3d when the concentration of dry powder reached 1.6 g/L, or in 2 d with the concentration of ethanol extracts reached 0.8 g/L. The latter exhibited stronger inhibition effects on C.closterium than the former because the concentration of ethanol extracts was expressed by the quality of dry powder before it was extracted. Under 1.6 g/L of ethanol extracts, the nuclei of C.closterium were broken in several hours. Up to 24 h, the cell membrane became obscure and difficult to be recognized, the whole cell shrank seriously and broke into fragments gradually.