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Influence of mixed antibiotics on Microcystis aeruginosa during the application of glyphosate and hydrogen peroxide algaecides
Author(s) -
Yu Shikun,
Liu Ying,
Zhang Jian,
Gao Baoyu
Publication year - 2019
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/jpy.12832
Subject(s) - microcystis aeruginosa , antibiotics , superoxide dismutase , biology , hydrogen peroxide , tetracycline , microbiology and biotechnology , cyanobacteria , malondialdehyde , food science , environmental chemistry , oxidative stress , chemistry , biochemistry , bacteria , genetics
Antibiotics regulate various physiological functions in cyanobacteria and may interfere with the control of cyanobacterial blooms during the application of algaecides. In this study, Microcystis aeruginosa was exposed to H 2 O 2 and glyphosate for 7 d in the presence of coexisting mixed antibiotics (amoxicillin, spiramycin, tetracycline, ciprofloxacin, and sulfamethoxazole) at an environmentally relevant concentration of 100 ng · L −1 . The mixed antibiotics significantly ( P < 0.05) alleviated the growth inhibition effect of 15–45 μM H 2 O 2 and 40–60 mg · L −1 glyphosate. According to the increased contents of chlorophyll a and protein, decreased content of malondialdehyde, and decreased activities of superoxide dismutase and glutathione S‐transferase, antibiotics may reduce the toxicity of the two algaecides through the stimulation of photosynthesis and the reduction in oxidative stress. The presence of coexisting antibiotics stimulated the production and release of microcystins in the M. aeruginosa exposed to low concentrations of algaecides and posed an increased threat to aquatic environments. To eliminate the secondary pollution caused by microcystins, high algaecide doses that are ≥45 μM for H 2 O 2 and ≥60 mg · L −1 for glyphosate are recommended. This study provides insights into the ecological hazards of antibiotic contaminants and the best management practices for cyanobacterial removal under combined antibiotic pollution conditions.