College of Environment, Zhejiang University of Technology, Hangzhou 310032, China.
College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China.
J Environ Sci (China). 2021 Jan;99:1-9. doi: 10.1016/j.jes.2020.06.001. Epub 2020 Jun 21.
Freshwater cyanobacterial blooms have drawn public attention because they threaten the safety of water resources and human health worldwide. Heavy cyanobacterial blooms outbreak in Lake Taihu in summer annually and vanish in other months. To find out the factors impacting the cyanobacterial blooms, the present study measured the physicochemical parameters of water and investigated the composition of microbial community using the 16S rRNA gene and internal transcribed spacer amplicon sequencing in the months with or without bloom. The most interesting finding is that two major cyanobacteria, Planktothrix and Microcystis, dramatically alternated during a cyanobacterial bloom in 2016, which is less mentioned in previous studies. When the temperature of the water began increasing in July, Planktothrix appeared first and showed as a superior competitor for M. aeruginosa in NO-rich conditions. Microcystis became the dominant genus when the water temperature increased further in August. Laboratory experiments confirmed the influence of temperature and the total dissolved nitrogen (TDN) form on the growth of Planktothrix and Microcystis in a co-culture system. Besides, species interactions between cyanobacteria and non-cyanobacterial microorganisms, especially the prokaryotes, also played a key role in the alteration of Planktothrix and Microcystis. The present study exhibited the alteration of two dominant cyanobacteria in the different bloom periods caused by the temperature, TDN forms as well as the species interactions. These results helped the better understanding of cyanobacterial blooms and the factors which contribute to them.
淡水蓝藻水华引起了公众的关注，因为它们威胁着全球水资源和人类健康的安全。太湖夏季每年都会发生严重的蓝藻水华，而在其他月份则消失。为了找出影响蓝藻水华的因素，本研究在有或没有水华的月份测量了水的理化参数，并使用 16S rRNA 基因和内部转录间隔区扩增子测序调查了微生物群落的组成。最有趣的发现是，两种主要的蓝藻——束丝藻和微囊藻——在 2016 年的一次蓝藻水华期间剧烈交替，这在以前的研究中较少提及。当水温在 7 月开始升高时，束丝藻首先出现，并在富含硝酸盐的条件下表现出对铜绿微囊藻的优势竞争。当水温在 8 月进一步升高时，微囊藻成为优势属。实验室实验证实了温度和总溶解氮（TDN）形式对束丝藻和微囊藻在共培养系统中生长的影响。此外，蓝藻和非蓝藻微生物之间的种间相互作用，特别是原核生物，在束丝藻和微囊藻的变化中也起着关键作用。本研究展示了两种主要蓝藻在不同水华期因温度、TDN 形式以及种间相互作用而发生的变化。这些结果有助于更好地理解蓝藻水华及其形成的因素。
