Seasonal shifts in chemotype composition of Microcystis sp communities in the pelagial and the sediment of a shallow reservoir
Seasonal shifts in chemotype composition of Microcystis sp communities in the pelagial and the sediment of a shallow reservoir
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DOI：
10.4319/lo.2007.52.2.0609
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发表时间：
2007-03-01
影响因子：
4.5
通讯作者：
Marsalek, Blahoslav
中科院分区：
文献类型：
--
作者：
Welker, Martin;Sejnohova, Lenka;Marsalek, Blahoslav
由单个微囊藻克隆产生的各种寡肽使得能够将微囊藻的单个菌落分类为不同的肽化学型。共存的化学型的动态和多样性被认为是影响这一潜在的有毒蓝藻属水华的微囊藻毒素含量的主要因素。我们比较了2004年7月至11月在布尔诺水库（捷克共和国）的浮游和底栖微囊藻群落的化学型组成的单菌落质谱法（n = 783）。选择92个肽来表征37个化学型，如通过K-均值聚类所揭示的。在这个季节的过程中，微囊藻群落变得显着减少多样性（香农指数的线性回归，p < 0.001），在远洋，并在11月两个化学型，这两个都不包含微囊藻毒素占近80%的殖民地。相比之下，其他化学型，占主导地位的中上层在7月后不再遇到8月，而一些化学型，从来没有占高相对丰度遇到整个赛季。深海层向少数几种主要化学型的转变也反映在底栖生物群落的变化上，其中相同化学型的相对丰度有所增加。尽管如此，在7月和11月的沉积物中发现了从未在浮游生物样本中发现的化学型。主成分分析表明，在浮游和底栖的社区是非常不同的，在7月，但收敛的季节，因为沉积物中占主导地位的浮游化学型。随着产毒微囊藻菌落百分比的下降，悬浮物样品中微囊藻毒素含量从0.9 mg g（-1）干重显著下降至检测限以下（线性回归，p < 0.001）。
The various oligopeptides produced by individual Microcystis clones enable the classification of individual colonies of Microcystis in distinct peptide chemotypes. The dynamics and diversity of coexisting chemotypes are regarded as major factors influencing the microcystin-content of blooms of this potentially toxic cyanobacterial genus. We compared the chemotype composition in planktonic and benthic Microcystis communities in Brno reservoir (Czech Republic) from July to November 2004 by single-colony mass spectrometry (n = 783). Ninety-two peptides were selected to characterize 37 chemotypes as revealed by K-means clustering. In the course of the season the Microcystis community became significantly less diverse (linear regression of Shannon indices, p < 0.001) in the pelagic, and in November two chemotypes-both of which did not contain microcystins-accounted for nearly 80% of the colonies. In contrast, other chemotypes that were dominant in the pelagic in July were no longer encountered after August, whereas some chemotypes that never accounted for high relative abundances were encountered throughout the season. The shift to some few dominant chemotypes in the pelagic was also reflected by changes in the benthic community where the same chemotypes increased in relative abundances. Nonetheless, chemotypes were identified in the sediment in July and November that were never found in plankton samples. A principal component analysis revealed that communities in the pelagial and the benthal were very different in July but converged during the season because of the deposition of dominant planktonic chemotypes in the sediment. in accordance with the declining percentage of toxin-producing Microcystis colonies, the microcystin content of seston samples decreased significantly from 0.9 mg g(-1) dry weight to levels below the detection limit (linear regression, p < 0.001).