| 温度与光强对柔细束丝藻3种异味物质产量的影响 |
| Effects of Temperature and Light on Production of Three Odorous Compounds by Aphanizomenon gracile |
| 投稿时间：2015-03-20 修订日期：2015-09-16 |
| DOI：10.15928/j.1674-3075.2015.04.011 |
| 中文关键词:温度 光强 柔细束丝藻 β-环柠檬醛 土臭素 β-紫罗兰酮 |
| 英文关键词:temperature light intensity Aphanizomenon gracile β-Cyclocitral geosmin β-Ionone |
| 基金项目:水体污染控制与治理科技重大专项滇池项目(2013ZX07102-005)。 |
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| 中文摘要: |
| 2013年3月从武汉喷泉公园人工湖发生水华并散发浓烈异味的水体中分离到1株柔细束丝藻(Aphanizomenon gracile)，编号为WH-1，通过探究温度和光强对其生长及异味物质产量的影响，为水体异味物质的防治与消除提供理论依据。经顶空固相微萃取法(HS-SPME)，鉴定其产3种异味物质，分别是β-环柠檬醛(β-Cyclocitral)、土臭素(Geosmin)和β-紫罗兰酮(β-Ionone)；实验室条件下研究不同温度(15、25、35℃)、光强[15、25、35 μmol/（m2.s)]对该藻株生长及3种异味物质产量的影响。结果表明，WH-1的最适生长条件和最大Geosmin产量均出现在低温(15℃)、高光强[35 μmol/（m2.s)]的条件下，但溶解态Geosmin的产量并未显著高于其它处理组。不利的生长条件[25～35℃，15～25 μmol/（m2.s)]有利于异味物质β-Cyclocitral和β-Ionone在藻细胞内积累。培养过程中，溶解态β-Cyclocitral和β-Ionone一直维持较低水平(检测线附近波动)，表明该类异味物质主要存储在细胞内部，在藻类生长过程中仅少量释放出来。3种异味物质所占比例变化说明，与光强相比，温度对异味物质产量的影响更大。 |
| 英文摘要: |
| Cyanobacteria blooms not only influence water quality, but also produce secondary metabolites including toxins and odorous compounds. Research indicates that cyanobacteria are the primary producer of off-flavor episodes in water bodies. Aphanizomenon gracile is observed in water bodies worldwide and often becomes the dominant species in freshwater cyanobacteria blooms because it is highly adaptable to a range of environmental conditions. Summer is the season when off-flavor episodes are most frequent due to high temperature, but research has confirmed that low temperature and low light favor the accumulation of odorous compounds. In this investigation, we studied the effects of temperature and light intensity on the growth and off-flavor production of Aphanizomenon gracile, as well as the allocation of extra- and intracellular production of odorous compounds. The study provides a theoretical basis for control and removal of substances that give off-flavor to water. A cyanobacteria strain, labeled as WH-1, was isolated from a lake with an odorous algal bloom in Wuhan Fountain Park in March, 2013, and identified as Aphanizomenon gracile. The cyanobacteria was cultured in aerated BG11 medium at 25±1°C, under an illumination of 20 μmol/(m2.s) and a photoperiod cycle of 12 h light:12 h dark. Aphanizomenon gracile in the exponential growth phase was removed from the medium and centrifuged. Flasks containing BG-11 medium was inoculated with the cells, which were then cultured at three temperatures (15, 25 and 35°C) and three light intensities (15, 25, 35 μmol/(m2.s)), with all treatments run in triplicate. Total and dissolved concentrations of the three odorous compounds were determined every 5 days. The substances responsible for the off-flavor episodes, β-Cyclocitral, geosmin and β-Ionone, were analyzed by head space solid phase micro-extraction (HS-SPME). Results indicate the following: (1) Low temperature (15°C) and high light intensity (35 μmol/(m2.s)) promote the growth of Aphanizomenon gracile. (2) Production of geosmin is positively related to the growth of Aphanizomenon gracile but dissolved geosmin in the low temperature and high light treatments was not significantly higher than in other treatment groups. (3) Higher temperature (25-35°C) and lower light intensity [15-25 μmol/(m2.s)] favors the accumulation of β-Cyclocitral and β-Ionone in cells. (4) Dissolved β-Cyclocitral and β-Ionone always remained at low levels (near the detection limit), suggesting that β-Cyclocitral and β-Ionone are primarily stored in cells and only small amounts are released. (5) Temperature has a larger effect than light intensity on the production of the three odorous compounds by Aphanizomenon gracile. |
| 周维成,王素钦,高翔,郭亮亮,代亮亮,李根保.2015.温度与光强对柔细束丝藻3种异味物质产量的影响[J].水生态学杂志,36(4):78-85. |
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