Dynamics of the prokaryotic and eukaryotic microbial community during a cyanobacterial bloom

Oct 18, 2021·
Yilin Qian
,
Kunihiro Okano
,
Miwa Kodato
,
Michiko Arai
,
Takeru Yanagiya
,
Qintong Li
Chie Amano
Chie Amano
,
Kakeru Ruike
,
Tomoaki Itayama
,
Norio Iwami
,
Motoo Utsumi
,
Zhongfang Lei
,
Zhenya Zhang
,
Norio Sugiura
,
Kazuya Shimizu
· 1 min read
DOI
publication

Toxic cyanobacterial blooms frequently develop in eutrophic freshwater bodies worldwide. Microcystis species produce microcystins (MCs) as a cyanotoxin. Certain bacteria that harbor the mlr gene cluster, especially mlrA, are capable of degrading MCs. However, MC-degrading bacteria may possess or lack mlr genes (mlr+ and mlr− genotypes, respectively). In this study, we investigated the genotype that predominantly contributes to biodegradation and cyanobacterial predator community structure with change in total MC concentration in an aquatic environment. The 2 genotypes coexisted but mlr+ predominated, as indicated by the negative correlation between mlrA gene copy abundance and total MC concentration. At the highest MC concentrations, predation pressure by Phyllopoda, Copepoda, and Monogononta (rotifers) was reduced; thus, MCs may be toxic to cyanobacterial predators. The results suggest that cooperation between MC-degrading bacteria and predators may reduce Microcystis abundance and MC concentration.

Cyanobacterial Bloom Microbial Community Prokaryotes Eukaryotes
Chie Amano
Authors
Chie Amano
Associate Professor
Chie Amano is a marine microbial ecologist studying the role of bacteria and archaea in the ocean’s biogeochemical cycles, with a focus on the dark, deep ocean. Her research addresses both sides of the carbon cycle: the heterotrophic degradation of organic matter, including by particle-associated communities, and dark inorganic carbon fixation through anaplerotic and chemolithoautotrophic processes. She also examines how hydrostatic pressure shapes microbial activity and carbon cycling in the deep sea, and she develops single-cell approaches such as BONCAT and microautoradiography, together with in situ instrumentation, to quantify microbial activity in the deep ocean.