Algicidal Activity of Streptomyces eurocidicus JXJ-0089 Metabolites and Their Effects on Microcystis Physiology.
Copper sulfate (CuSO4) has been widely used as an algicide to control harmful cyanobacterial blooms (CyanoHABs) in freshwater lakes. However, there are increasing concerns about this application, due mainly to the general toxicity of CuSO4 to other aquatic species and its long-term persistence in the environment. This study reported the isolation and characterization of two natural algicidal compounds, i.e., tryptamine and tryptoline, from Streptomyces eurocidicus JXJ-0089. At a concentration of 5 μg/ml, both compounds showed higher algicidal efficiencies than CuSO4 on Microcystis sp. FACHB-905 and some other harmful cyanobacterial strains. Tryptamine and tryptoline treatments induced a degradation of chlorophyll and cell walls of cyanobacteria. These two compounds also significantly increased the intracellular oxidant content, i.e., superoxide anion radical (O2 (-)) and malondialdehyde (MDA), but reduced the activity of intracellular reductants, i.e., superoxide dismutase (SOD), of cyanobacteria. Moreover, tryptamine and tryptoline treatments significantly altered the internal and external contents of microcystin-LR (MC-LR), a common cyanotoxin. Like CuSO4, tryptamine and tryptoline led to releases of intracellular MC-LR from Microcystis, but with lower rates than CuSO4 Tryptamine and tryptoline (5 μg/ml) in cyanobacterial cultures were completely degraded within 8 days, while CuSO4 persisted for months. Overall, our results suggest that tryptamine and tryptoline could potentially serve as more efficient and environmentally friendly alternative algicides than CuSO4 in controlling harmful cyanobacterial blooms.



Cyanobacterial harmful algal blooms (CyanoHABs) in aquatic environments have become a worldwide problem. Numerous efforts have been made to seek means to prevent, control, and mitigate CyanoHABs. Copper sulfate (CuSO4), was once a common algicide to treat and control CyanoHABs. However, its application has become limited due to concerns about its general toxicity to other aquatic species and its long-term persistence in the environment. There is a great need for algicides with higher specificity and low environmental impacts. This study reports the isolation and characterization of two natural algicidal compounds from a streptomycete strain, Streptomyces eurocidicus JXJ-0089. Our results suggest that the identified algicides could potentially serve as more efficient and environmentally friendly alternative algicides than CuSO4 in controlling harmful cyanobacterial blooms.
College of Life Science, Jiujiang University, Jiujiang, People's Republic of China State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
Bing-Huo
BH
Zhang
Yunnan Institute of Microbiology, Yunnan University, Kunming, People's Republic of China.
Zhang-Gui
ZG
Ding
College of Life Science, Jiujiang University, Jiujiang, People's Republic of China.
Han-Quan
HQ
Li
Department of Biological Sciences, Kent State University, Kent, Ohio, USA xmou@kent.edu liwenjun3@mail.sysu.edu.cn.
Xiao-Zhen
XZ
Mou
Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
Yu-Qin
YQ
Zhang
College of Life Science, Jiujiang University, Jiujiang, People's Republic of China.
Jian-Yuan
JY
Yang
State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China Yunnan Institute of Microbiology, Yunnan University, Kunming, People's Republic of China.
En-Min
EM
Zhou
State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China Yunnan Institute of Microbiology, Yunnan University, Kunming, People's Republic of China xmou@kent.edu liwenjun3@mail.sysu.edu.cn.
Wen-Jun
WJ
Li
D002243:Carbolines / Q000378:metabolism / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism; D057097:Harmful Algal Bloom / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D046931:Microcystis / Q000187:drug effects* / Q000502:physiology; D013302:Streptomyces / Q000737:chemistry* / Q000378:metabolism*; D014363:Tryptamines / Q000378:metabolism / Q000494:pharmacology*
D002243:Carbolines; D014363:Tryptamines; D002734:Chlorophyll; C030820:tryptamine; D008315:Malondialdehyde; C009804:tryptoline