| 滇池微囊藻沉降细胞生理特性及沉降比率动态变化研究 |
| 摘要点击 1919 全文点击 2047 投稿时间：2009-05-04 修订日期：2009-07-20 |
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| 中文关键词 微囊藻 沉降 漂浮 氧还脱氢酶 滇池 |
| 英文关键词 Microcystis sinking floating dehydrogenases Lake Dianchi |
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| 中文摘要 |
| 通过比较滇池漂浮细胞与沉降细胞生理活性差异，比较表层水样与底层水样沉降比率、活细胞的比例，揭示沉降细胞的生理特征，进而调查沉降比率与叶绿素a含量的动态变化，探讨藻细胞沉降与微囊藻水华发展趋势的关系.野外水样在室内放置2 h后，漂浮细胞与沉降细胞在水柱中基本稳定.沉降细胞PSⅡ的最大光化学效率、细胞膜完整性与漂浮细胞无显著性差异（p>0.05），但沉降细胞电子传递速率，尼克酰胺腺嘌呤二核苷酸(磷酸)[NAD(P)H]依赖型氧还脱氢酶活性显著低于漂浮细胞（p<0.01）.比较表层样品与底层样品，底层样品沉降比率显著高于表层样品（p<0.01），噻唑蓝(MTT)阴性细胞比率也显著高于表层样品（p<0.01）.这些结果表明，沉降细胞受到损伤，代谢活性下降.在2007年10月～2008年5月研究期间内，表层水样沉降比率在冬季最高达40%，沉降比率的动态变化与水体叶绿素a浓度变化呈负相关（p<0.05）.藻细胞的沉降是微囊藻水华衰退的重要原因，沉降比率的研究将有助于了解水体微囊藻水华发生发展，沉降细胞生理特性研究为将沉降比率引入微囊藻水华发展趋势预测提供了理论依据. |
| 英文摘要 |
| Aimed to explore the relationship between Microcystis cells sinking and water bloom development,the physiological status of the sinking cells was characterized by comparing with the floating cells. The sinking ratio and the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) staining were also employed in surface and bottom samples to substantiate the character. The dynamics of the sinking ratio and the chlorophyll a concentration were also compared. The field Microcystis cells had relative stable positions in the sample container after 2 hours settlement in the lab. Statistic analysis suggested that the floating and the sinking colonies did not differ significantly on the indicators maximum quantum yield of PSⅡ and membrane integrity（p>0.05）,but did significantly on the electron transfer rate and nicotinamide adenine dinucleotide (phosphate),reduced disodium salt [NAD(P)H] dependent oxidoreductase and dehydrogenase activities（p<0.01）. Furthermore,comparison between bottom samples and surface samples suggested the bottom had higher ratio of sinking and MTT negative cells（p<0.01）. These results implied that the sinking cells were injured and had lower metabolic activity. During the time from October 2007 to May 2008,the sinking ratio reached climax about 40% in winter,and a negative correlation between the sinking ratio and chlorophyll a concentration was observed （p<0.05）. Sinking played an important role in the decline of Microcystis bloom. A research on the sinking ratio will be helpful for the understanding of bloom development tendency. The characterization on the physiology status of sinking cells constructed basement for the introduction of sinking ratio to the prediction of water bloom development. |
