Key laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Department of Urban Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Department of Urban Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
J Environ Sci (China). 2019 Feb;76:359-367. doi: 10.1016/j.jes.2018.05.029. Epub 2018 Jun 9.
Microcystis panniformis is a bloom forming species with flat panniform-like colonies. This species was recently found in Lake Taihu, China. To specifically characterize M. panniformis based on isolated strains, morphological examination on colonial transition and genetic examination are needed. Three M. panniformis strains isolated from a water bloom sample in Lake Taihu were characterized by molecular analysis and toxin quantification. Phylogenetic analysis based on both 16S rRNA gene and internal transcribed spacer (ITS) between 16S and 23S rRNA genes were performed and compared to facilitate easy identification of the species. Relatively high similarities (98%-99%) were shown in 16S rDNA sequences between the strains of M. panniformis and those of other Microcystis species, whereas the similarities for ITS sequences were 88%-95%. In the phylogenetic tree based on the 16S rDNA sequences, the M. panniformis and M. aeruginosa strains were intermixed together with no clear division, whereas all of the M. panniformis strains were clustered together in a single clade based on the ITS sequences based phylogenyetic tree. The mcyE gene was detected in all three strains, and microcystin was determined by high-performance liquid chromatography. The molecular detection and toxin production of M. panniformis strains are of great significance for the environmental risk assessment of Microcystis blooms.
微囊藻是一种具有扁平囊状结构的水华形成物种。该物种最近在中国太湖被发现。为了基于分离株对微囊藻进行具体特征描述，需要进行形态学上的群体转化检查和遗传学检查。从太湖水华样本中分离得到的三株微囊藻通过分子分析和毒素定量进行了特征描述。基于 16S rRNA 基因和 16S 与 23S rRNA 基因之间的内部转录间隔区（ITS）进行了系统发育分析，并进行了比较，以方便对该物种进行鉴定。微囊藻菌株的 16S rDNA 序列之间具有相对较高的相似性（98％-99％），而 ITS 序列的相似性为 88％-95％。在基于 16S rDNA 序列的系统发育树中，微囊藻和铜绿微囊藻的菌株混合在一起，没有明显的划分，而所有的微囊藻菌株都根据 ITS 序列的系统发育树聚类在一起。在所有三株菌中均检测到了 mcyE 基因，并且通过高效液相色谱法确定了微囊藻毒素。微囊藻菌株的分子检测和毒素产生对于微囊藻水华的环境风险评估具有重要意义。
