Effects of the algicide, thiazolidinedione derivative TD49, on microbial communities in a mesocosm experiment.
We investigated the effects of the algicide thiazolidinedione derivative TD49 on microbial community in mesocosm experiments. The TD49 concentration exponentially decreased over time, with half-life of 3.5 h, following addition in the seawater (R2=0.98, P<0.001). Among microbial communities, heterotrophic bacteria and heterotrophic nanoflagellates (HNFs) grew well in all treatments following the addition of TD49. The abundance of HNFs lagged behind the increase in heterotrophic bacteria by 24 h in the 0.2 and 0.4 μM TD49 concentrations (R2=0.28, P<0.05), and by 48 h in the 0.6 and 1.0 μM TD49 concentrations (R2=0.30, P<0.05). This implies a strong concentration-dependent top-down effect of TD49 on microbial communities, with indications that the degradation of planktonic organisms, including the target alga, led to high heterotrophic bacteria concentrations, which in turn stimulated the population growth of predatory HNF. However, total ciliate numbers remained relatively low in the TD49 treatments relative to the control and blank groups, suggesting limited carbon flow from bacteria to these grazers even though the abundance of aloricate ciliates gradually increased toward the end of the experimental period, particularly at the high TD49 concentrations. TD49 appears to provide an environmentally safe approach to the control of harmful algal blooms (HABs) in aquatic ecosystems.
South Sea Institute, Korea Institute of Ocean Science and Technology (KIOST), Geoje, 656-830, Republic of Korea.
Moonho
M
Son
Seung Ho
SH
Baek
Kyoungsoon
K
Shin
Keun-Hyung
KH
Choi
Si Wouk
SW
Kim
Jaewon
J
Ryu
Hoon
H
Cho
Seung Won
SW
Jung
Ik Kyo
IK
Chung
Young-Ok
YO
Kim
Myung-Soo
MS
Han
D000890:Anti-Infective Agents / Q000633:toxicity*; D059001:Aquatic Organisms / Q000187:drug effects*; D001419:Bacteria / Q000254:growth & development; D002244:Carbon / Q000378:metabolism; D016798:Ciliophora; D017753:Ecosystem; D004784:Environmental Monitoring; D006207:Half-Life; D057097:Harmful Algal Bloom; D006540:Herbicides / Q000378:metabolism; D012623:Seawater; D045162:Thiazolidinediones / Q000633:toxicity*
D000890:Anti-Infective Agents; D006540:Herbicides; C570619:TD49 thiazolidinedione; D045162:Thiazolidinediones; D002244:Carbon