State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
Chemosphere. 2018 Oct;209:730-738. doi: 10.1016/j.chemosphere.2018.06.141. Epub 2018 Jun 26.
Cyanobacterial blooms as a global environmental issue are of public health concern. In this study, we investigated the spatial (10 sites) and temporal (June, August and October) variations in: 1) their biomass based on chlorophyll-a (chl-a) concentration, 2) their toxic genotype based on gene copy ratio of mcyJ to cpcBA, and 3) their cpcBA genotype composition of Microcystis during cyanobacterial bloom in Lake Taihu. While spatial-temporal variations were found in chl-a and mcyJ/cpcBA ratio, only spatial variation was observed in cpcBA genotype composition. Samples from northwestern part had a higher chl-a, but mcyJ/cpcBA ratio didn't vary among the sites. High chl-a was observed in August, while mcyJ/cpcBA ratio and genotypic richness increased with time. The spatial variations in chl-a and mcyJ/cpcBA ratio and temporal variation in cpcBA genotype were correlated negatively with dissolved N and positively with dissolved P. Spatial distribution of Microcystis biomass was positively correlated with nitrite and P excluding October, but no correlation was found for spatial distribution of mcyJ/cpcBA ratio and cpcBA genotype. Spatial distribution of toxic and cpcBA genotypes may result from horizontal transport of Microcystis colonies, while spatial variation in Microcystis biomass was probably controlled by both nutrient-mediated growth and horizontal transport of Microcystis. The temporal variation in Microcystis biomass, toxic genotype and cpcBA genotype composition were related to nutrient levels, but cause-and-effect relationships require further study.
蓝藻水华作为一个全球性的环境问题，引起了公众对健康的关注。在这项研究中，我们调查了太湖蓝藻水华期间：1）基于叶绿素-a（chl-a）浓度的生物量，2）基于 mcyJ 基因与 cpcBA 基因拷贝数比值的毒性基因型，3）基于 Microcystis 的 cpcBA 基因型组成的空间（10 个地点）和时间（6 月、8 月和 10 月）变化。虽然在 chl-a 和 mcyJ/cpcBA 比值方面发现了时空变化，但只有在 cpcBA 基因型组成方面观察到了空间变化。来自西北部的样品具有更高的 chl-a，但 mcyJ/cpcBA 比值在各地点之间没有差异。8 月份观察到高 chl-a，而 mcyJ/cpcBA 比值和基因型丰富度随时间增加。chl-a 和 mcyJ/cpcBA 比值的空间变化以及 cpcBA 基因型的时间变化与溶解氮呈负相关，与溶解磷呈正相关。Microcystis 生物量的空间分布与亚硝酸盐呈正相关，除 10 月外，与 P 也呈正相关，但 mcyJ/cpcBA 比值和 cpcBA 基因型的空间分布没有相关性。有毒和 cpcBA 基因型的空间分布可能是由于 Microcystis 菌落的水平运输所致，而 Microcystis 生物量的空间变化可能受到营养物质介导的生长和 Microcystis 的水平运输的共同控制。Microcystis 生物量、有毒基因型和 cpcBA 基因型组成的时间变化与营养水平有关，但因果关系需要进一步研究。
