菹草提取物对3种赤潮微藻生长的抑制作用

Growth Inhibition of the Three Species of Red Tide Microalgae by Extracts from Potamogeton crispus

摘要: 以甲醇浸泡菹草干粉4 d，过滤、减压蒸干后，制备到菹草甲醇浸膏。此浸膏用90%甲醇水溶液(V/V)溶解后，依次以石油醚、乙酸乙酯和正丁醇为溶剂，采用液液萃取法进一步分离。经过滤、减压蒸干，获得4种液液分离提取物-石油醚、乙酸乙酯、正丁醇和蒸馏水提取物，得率分别为38.5%、21.9%、9.37%和26.6%。在此基础上，通过测定藻细胞数量，观察藻细胞形态，分析藻细胞内叶绿素、蛋白质和多糖含量等生理指标的变化，研究了此4种液液分离提取物对米氏凯伦藻(Karenia mikimitoi)、中肋骨条藻(Skeletonema costatum)和塔玛亚历山大藻(Alexandrium tamarense)生长的影响。结果表明，石油醚和乙酸乙酯提取物能明显降低3种赤潮微藻的细胞数量。当提取物浓度为16 mg/L时，此2种提取物对3种赤潮微藻的生长抑制率超过66%(第12 d)。同时，此2种提取物显著改变了3种赤潮微藻的细胞形态，致使藻细胞出现空洞、破碎和色素明显减褪现象。并且，它们还能显著影响藻细胞内叶绿素、蛋白质和多糖等生理指标的合成。在实验设定浓度范围内，正丁醇和蒸馏水提取物未对3种赤潮微藻的生长产生明显的影响。

Abstract: To study effects of solvent-partitioned fractions of methanol extracts from Potamogeton crispus on the growth of the three species of microalgae (Karenia mikimitoi, Skeletonema costatum and Alexandrium tamarense), the extracts were extracted with petroleum ether, ethyl acetate, n-butanol and distilled water by liquid-liquid fractionaction, respectively. And yields of solvent-partitioned fractions were 38.5% petroleum ether extracts, 21.9% ethyl acetate extracts, 9.37% n-butanol extracts and 26.6% distilled water extracts, respectively. Based on the observation of algal morphology and the measurement of algal number, and the contents of physiological indicators (protein, polysaccharide and chlorophyll), the results showed the petro- leum ether extracts and ethyl acetate extracts from methanol extracts of Potamogeton crispus had the stron- gest action. The inhibitory effect of the tested microalgae by these two extracts was above 66% in day 12 at the concentration of 16 mg/L. And the petroleum ether extracts and ethyl acetate extracts caused cavities, pieces and chlorophyll decreased in cells. The further investigation found that these two extracts significantly decreased the contents of protein, polysaccharide and chlorophyll in the cells of those microalgae. But n- butanol extracts and distilled water extracts had not significant affect the growth of the all test microalgae.