Integrated inactivation of Microcystis aeruginosa by allelochemicals and a flow-through copper ionization cell: performance insights and mechanisms

Abstract

Harmful algal blooms represent a significant global challenge. In this study, we integrated allelochemicals with a flow-through copper ionization cell to inhibit Microcystis aeruginosa. Our findings revealed that the combined treatment achieved maximum inhibition rates of 84.39% and 79.55% for toxic and non-toxic M. aeruginosa, respectively, after seven days. These results demonstrated significantly stronger inhibition compared to individual treatments, including L-lysine (38.62% and 27.73%), electric field treatment (64.45% and 56.67%), and copper ionization cell (less than 20%) applications. The combined treatment induced more substantial reductions in chlorophyll a, carotenoids, and phycobiliproteins, causing greater damage to the photosynthetic system. Notably, phycocyanin content exhibited the most pronounced decline, suggesting its potential as a critical target for intervention. Furthermore, the combined stress triggered the highest levels of oxidative stress and disruption of antioxidant enzymes in algal cells, ultimately leading to programmed cell death-like responses. These findings provide valuable insights into a promising strategy for cyanobacteria control.

Graphical abstract

Keywords

Microcystis aeruginosa, L-lysine / A flow-through copper ionization cell / Combined action / Programmed cell death-like

Highlight

	● L-lysine combined with copper ionization cell suppressed M. aeruginosa growth.
	● The combined inhibition of M. aeruginosa was far exceeding single treatments.
	● The combination resulted in greater damage to the photosynthetic system.
	● The significant reduction of phycocyanins suggests it may be a key target.
	● Combined treatment induced the programmed cell death-like of M. aeruginosa.

References

[1] Akbarbaglu ZTamjidi FSarabandi KSamborska KJafari S M (2025). Stabilization of Arthrospira phycocyanin within structurally modified whey protein: thermal, biological, and photo-stability and a natural blue-colorant in gummy-candy. International Journal of Biological Macromolecules, 329(Pt 2): 147920

[2] Bai F , Jia Y L , Li J , Wu Z X , Li L , Song L R . (2023). Paraquat induces different programmed cell death patterns in Microcystis aeruginosa and Chlorella luteoviridis. Ecotoxicology and Environmental Safety, 249: 114429

[3] Bennett A , Bogorad L . (1973). Complementary chromatic adaptation in a filamentous blue-green alga. Journal of Cell Biology, 58(2): 419–435

[4] Bhatti A F , Choubeh R R , Kirilovsky D , Wientjes E , van Amerongen . (2020). State transitions in cyanobacteria studied with picosecond fluorescence at room temperature. Biochimica et Biophysica Acta (BBA)-Bioenergetics, 1861(10): 148255

[5] Chen Y T , Weng Y Y , Zhou M , Meng Y Y , Liu J L , Yang L , Zuo Z J . (2019). Linalool-and α-terpineol-induced programmed cell death in Chlamydomonas reinhardtii. Ecotoxicology and Environmental Safety, 167: 435–440

[6] Cupellini L , Gwizdala M , Krüger T P J . (2024). Energetic landscape and terminal emitters of phycobilisome cores from quantum chemical modeling. The Journal of Physical Chemistry Letters, 15(38): 9746–9756

[7] Dahedl E K , Hancock T L , Kratz M A , Urakawa H . (2025). A combination cyanobacterial treatment approach using hydrogen peroxide and L-lysine successfully improved the removal efficiency of toxic cyanobacteria. Journal of Environmental Management, 373: 123503

[8] Fan G D , Zhou J J , Zheng X M , Chen W . (2018). Growth inhibition of Microcystis aeruginosa by copper-based MOFs: performance and physiological effect on algal cells. Applied Organometallic Chemistry, 32(12): e4600

[9] Fan S J , Li W Z , Chen Z , Wang Z X , Cheng X , Zhang S S , Dai M X , Yang J Y , Chen L L , Zhao G Y . (2025). Pyridoxine dehydro-genase SePdx regulates photosynthesis via an association with the phycobilisome in a cyanobacterium. The Plant Journal, 121(6): e70055

[10] Fu L J , Li D , Wu C J , Zheng T L . (2012). Effects of algicidal bacterium BS03 (Microbulbifer sp.) on the growth and antioxidant systems of Alexandrium tamarense. Acta Microbiologica Sinica, 52(6): 784–790

[11] Geng C Y , Zhou B Y , Calabrese E J , Agathokleous E . (2025). Stimulation of Microcystis aeruginosa by subtoxic concen-trations of contaminants: a meta-analysis. Environmental Research, 271: 121105

[12] Han M A X , Wang R J , Ding N , Liu X X , Zheng N N , Fu B Y , Sun L , Gao P K . (2018). Reactive oxygen species-mediated caspase-3 pathway involved in cell apoptosis of Karenia mikimotoi induced by linoleic acid. Algal Research, 36: 48–56

[13] Han S Q , Zhou Q , Lilje O , Xu W J , Zhu Y H , van Ogtrop F F . (2021). Inhibition mechanism of Penicillium chrysogenum on Microcystis aeruginosa in aquaculture water. Journal of Cleaner Production, 299: 126829

[14] Harke M J , Steffen M M , Gobler C J , Otten T G , Wilhelm S W , Wood S A , Paerl H W . (2016). A review of the global ecology, genomics, and biogeography of the toxic cyanobacterium, Microcystis spp. Harmful Algae, 54: 4–20

[15] Hennessey A V , McDonald M B , Johnson P P , Gladfelter M F , Merrill K L , Tenison S E , Ganegoda S S , Hoang T C , Torbert H A , Beck B H . et al. (2025). Evaluating the tolerance of harmful algal bloom communities to copper. Environmental Pollution, 368: 125691

[16] Hong Y , Hu H Y , Xie X , Sakoda A , Sagehashi M , Li F M . (2009). Gramine-induced growth inhibition, oxidative damage and antioxidant responses in freshwater cyanobacterium Microcystis aeruginosa. Aquatic Toxicology, 91(3): 262–269

[17] Hu C L , Rzymski P . (2019). Programmed cell death-like and accompanying release of microcystin in freshwater bloom-forming cyanobacterium Microcystis: from identification to ecological relevance. Toxins, 11(12): 706

[18] Huang H M , Xiao X , Lin F , Grossart H P , Nie Z Y , Sun L J , Xu C , Shi J Y . (2016). Continuous-release beads of natural allelo-chemicals for the long-term control of cyanobacterial growth: preparation, release dynamics and inhibitory effects. Water Research, 95: 113–123

[19] Krishnaraj C , Jagan E G , Ramachandran R , Abirami S M , Mohan N , Kalaichelvan P T . (2012). Effect of biologically synthesized silver nanoparticles on Bacopa monnieri (Linn.) Wettst. plant growth metabolism. Process Biochemistry, 47(4): 651–658

[20] Kriss R , Edwards M A . (2024). Guidance for residents addressing copper problems in drinking water: opportunities and challenges. ACS ES&T Water, 4(9): 4175–4183

[21] Li D , Wu N C , Tang S , Su G Y , Li X W , Zhang Y , Wang G X , Zhang J Y , Liu H L , Hecker M . et al. (2018). Factors associated with blooms of cyanobacteria in a large shallow lake, China. Environmental Sciences Europe, 30(1): 27

[22] Li M Y , Wang Q L , Guo W D , Zhou S B , Fan J L , Zhao L P , He Z , Lei Z W , Zhang Y H . (2025). Mechanism and kinetics for copper leaching by complexing with lysine bearing two amino groups. Langmuir, 41(16): 10230–10237

[23] Liang W WYang Q HWu G FLin S MYang J CFeng YHu J M (2017). Effects of taurine and L-arginine on the apoptosis of vascular smooth muscle cells in insulin resistance hypertensive rats. In: Lee D H, Schaffer S W, Park E, Kim H W, eds. Taurine 10. Dordrecht: Springer, 813–819

[24] Liu H Y , Chen S N , Zhang H H , Wang N , Ma B , Liu X , Niu L M , Yang F , Xu Y , Zhang X L . (2023). Effects of copper sulfate algaecide on the cell growth, physiological characteristics, the metabolic activity of Microcystis aeruginosa and raw water application. Journal of Hazardous Materials, 445: 130604

[25] Liu P R , Zhou J F , Hong Y , Xie X . (2020). Electric-field enhanced microalgae inactivation using a flow-through copper ionization cell. Journal of Hazardous Materials, 400: 123320

[26] Liu X , Wang X T , Zhang F W , Yao X F , Qiao Z H , Deng J H , Jiao Q , Gong L , Jiang X Y . (2022). Toxic effects of fludioxonil on the growth, photosynthetic activity, oxidative stress, cell morphology, apoptosis, and metabolism of Chlorella vulgaris. Science of the Total Environment, 838: 156069

[27] Mao Y F , Ye K L , Yang S F , Salam M , Yu W W , He Q , He R X , Li H . (2024). Repeated exposure enhanced toxicity of clarithromycin on Microcystis aeruginosa versus single exposure through photosynthesis, oxidative stress, and energy metabolism shift. Environmental Science & Technology, 58(9): 4070–4082

[28] Meghana S , Kabra P , Chakraborty S , Padmavathy N . (2015). Understanding the pathway of antibacterial activity of copper oxide nanoparticles. RSC Advances, 5(16): 12293–12299

[29] Ni L X , Wu H Q , Du C H , Li X L , Li Y , Xu C , Wang P F , Li S Y , Zhang J H , Chen X Q . (2021). Effects of allelochemical artemisinin in Artemisia annua on Microcystis aeruginosa: growth, death mode, and microcystin-LR changes. Environ-mental Science and Pollution Research, 28(33): 45253–45265

[30] Oh S , Montgomery B L . (2019). Roles of CpcF and CpcG1 in peroxiredoxin-mediated oxidative stress responses and cellular fitness in the cyanobacterium Synechocystis sp. PCC 6803. Frontiers in Microbiology, 10: 1059

[31] Pan D , Pavagadhi S , Umashankar S , Rai A , Benke P I , Rai M , Saxena G , Gangu V , Swarup S . (2019). Resource partitioning strategies during toxin production in Microcystis aeruginosa revealed by integrative omics analysis. Algal Research, 42: 101582

[32] Pei S Z , You S J , Ma J , Chen X D , Ren N Q . (2020). Electron spin resonance evidence for electro-generated hydroxyl radicals. Environmental Science & Technology, 54(20): 13333–13343

[33] Plaas H E , Paerl H W . (2021). Toxic cyanobacteria: a growing threat to water and air quality. Environmental Science & Technology, 55(1): 44–64

[34] Qi J , Jiang Y C , Ni R , Wang X , Hu C Z , Qu J H . (2024). Stress response of Microcystis aeruginosa to chlorine during transportation: the significance of surface-adsorbed organic matter. Water Research, 255: 121468

[35] Renaudin M , Darnajoux R , Bellenger J P . (2021). Quantification of moss-associated cyanobacteria using phycocyanin pigment extraction. Frontiers in Microbiology, 11: 611792

[36] Sheng H , Niu X J , Song Q , Li Y K , Zhang R Y , Zou D H , Lai S C , Yang Z Q , Tang Z H , Zhou S Q . (2019). Physiological and biochemical responses of Microcystis aeruginosa to phosphine. Environmental Pollution, 247: 165–171

[37] Song L Y , Wang Y Q . (2015). Investigation of microbial community structure of a shallow lake after one season copper sulfate algaecide treatment. Microbiological Research, 170: 105–113

[38] Soulier N , Bryant D A . (2021). The structural basis of far-red light absorbance by allophycocyanins. Photosynthesis Research, 147(1): 11–26

[39] Tang T , Huang H M , Hu J , Huang S T , Liu M Y , Yu S M , Xiao X . (2023). Discovery of novel anti-cyanobacterial allelochemicals by multi-conformational QSAR approach. Aquatic Toxicology, 256: 106420

[40] Tian L L , Chen M , Ren C Y , Wang Y Y , Li L . (2018). Anticyanobacterial effect of L-lysine on Microcystis aeruginosa. RSC Advances, 8(38): 21606–21612

[41] Viriyatum R , Boyd C E . (2016). Slow-release coated copper sulfate as an algicide for aquaculture. Journal of the World Aquaculture Society, 47(5): 667–675

[42] Wang T , Hu Y D , Zhu M , Yin S W . (2020). Integrated transcriptome and physiology analysis of Microcystis aeruginosa after exposure to copper sulfate. Journal of Oceanology and Limnology, 38(1): 102–113

[43] Wang T T , Liu H C . (2023). Aquatic plant allelochemicals inhibit the growth of microalgae and cyanobacteria in aquatic environments. Environmental Science and Pollution Research, 30(48): 105084–105098

[44] Wang X X , Szeto Y T , Jiang C C , Wang X J , Tao Y , Tu J G , Chen J . (2018a). Effects of Dracontomelon duperreanum leaf litter on the growth and photosynthesis of Microcystis aeruginosa. Bulletin of Environmental Contamination and Toxicology, 100(5): 690–694

[45] Wang X Y , Hong Y , Wang Z Y , Yuan Y Q , Sun D Z . (2024). High capacities of carbon capture and photosynthesis of a novel organic carbon-fixing microalgae in municipal wastewater: from mutagenesis, screening, ability evaluation to mechanism analysis. Water Research, 257: 121722

[46] Wang X Y , Zhao Y , Jiang X X , Wang Y Y , Li H X , Wang L , Liang W Y . (2018b). The growth and physiological activity of Microcystis aeruginosa after flocculation using modified tannin. International Biodeterioration & Biodegradation, 133: 180–186

[47] WHO (2011). Guidelines for Drinking Water Quality. 4th ed. Geneva: World Health Organization

[48] Xiao F , Wang C X , Yin H K , Yu J J , Chen S H , Fang J , Guo F F . (2016). Leucine deprivation inhibits proliferation and induces apoptosis of human breast cancer cells via fatty acid synthase. Oncotarget, 7(39): 63679–63689

[49] Xu C CYu S MHu JEffiong KGe Z WTang TXiao X (2022). Programmed cell death process in freshwater Microcystis aeruginosa and marine Phaeocystis globosa induced by a plant derived allelochemical. Science of the Total Environment, 838(Pt 2): 156055

[50] Xu H Y , Wang Y R , Lin K , Tan L J , Wang J T . (2024). Allelopathy of extracellular chemicals released by Karlodinium veneficum on photosynthesis of Prorocentrum donghaiense. Journal of Hazardous Materials, 476: 135079

[51] Yan X C , Xu X G , Wang M Y , Wang G X , Wu S J , Li Z C , Sun H , Shi A , Yang Y H . (2017). Climate warming and cyanobacteria blooms: looks at their relationships from a new perspective. Water Research, 125: 449–457

[52] Yan X J , Zhao F , Wang G S , Wang Z , Zhou M X , Zhang L M , Wang G X , Chen Y S . (2023). Metabolomic analysis of Microcystis aeruginosa after exposure to the algicide L-lysine. Bulletin of Environmental Contamination and Toxicology, 110(1): 12

[53] Zhang B H , Chen W , Li H Q , Yang J Y , Zha D M , Duan Y Q , Hozzein W N , Xiao M , Gao R , Li W J . (2016). L-valine, an antialgal amino acid from Streptomyces jiujiangensis JXJ 0074^T. Applied Microbiology and Biotechnology, 100(10): 4627–4636

[54] Zhang Z , Sun J , Zhang J J , Lin Y H , Xu Q L , Cui L H , Qiu R L , Huang Z J . (2025). Inactivation of Microcystis aeruginosa by magnetic cellulose combined with electroaggregation and electrooxidation. Separation and Purification Technology, 354: 128803

[55] Zhao M R , Sun L , Fu X J , Chen M . (2019). Phycoerythrin-phycocyanin aggregates and phycoerythrin aggregates from phycobilisomes of the marine red alga Polysiphonia urceolata. International Journal of Biological Macromolecules, 126: 685–696

[56] Zheng X W , Liu X L , Zhang L L , Wang Z M , Yuan Y , Li J , Li Y Y , Huang H H , Cao X , Fan Z Q . (2022). Toxicity mechanism of Nylon microplastics on Microcystis aeruginosa through three pathways: photosynthesis, oxidative stress and energy metabolism. Journal of Hazardous Materials, 426: 128094

[57] Zhou J F , Wang T , Xie X . (2019). Rationally designed tubular coaxial-electrode copper ionization cells (CECICs) harnessing non-uniform electric field for efficient water disinfection. Environment International, 128: 30–36

[58] Zhu J Y , Cai Y F , Wakisaka M , Yang Z F , Yin Y Q , Fang W M , Xu Y , Omura T , Yu R H , Zheng A L T . (2023). Mitigation of oxidative stress damage caused by abiotic stress to improve biomass yield of microalgae: a review. Science of the Total Environment, 896: 165200

[59] Zong P , Liu Y , Chen H , Miao S N , Lian K , Li C , Zhang H , Zhang M . (2022). Inhibitory mechanism of nano-copper carbon composite on Microcystis aeruginosa. Algal Research, 68: 102877

[60] Zuo S P , Yang H , Jiang X F , Ma Y Q . (2021). Magnetic Fe₃O₄ nanoparticles enhance cyanobactericidal effect of allelopathic p-hydroxybenzoic acid on Microcystis aeruginosa by enhancing hydroxyl radical production. Science of the Total Environment, 770: 145201

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