Aquatic environmental safety assessment and inhibition mechanism of chemicals for targeting Microcystis aeruginosa

Abstract

Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, fungi, bacteria and cell lines. Recently the main methods of controlling cyanobacteria are using chemicals, medicinal plants and microorganism but fewer involved the safety research in hydrophytic ecosystems. In search of an environmentally safe compound, 53 chemicals were screened against the developed heavy cyanobacteria bloom Microcystis aeruginosa using coexistence culture system assay. The results of the coexistence assay showed that 9 chemicals inhibited M. aeruginosa effectively at 20 mg L(-1) after 7 days of exposure. Among them dimethomorph, propineb, and paraquat were identified that they are safe for Chlorella vulgaris, Scenedesmus obliquus, Carassius auratus (Goldfish) and Bacillus subtilis within half maximal effective concentration (EC50) values 5.2, 4.2 and 0.06 mg L(-1) after 7 days, respectively. Paraquat as the positive control observed to be more efficient than the other compounds with the inhibitory rate (IR) of 92% at 0.5 mg L(-1). For the potential inhibition mechanism, the chemicals could destroy the cell ultrastructure in different speed. The safety assay proved dimethomorph, propineb and paraquat as harmless formulations or products having potential value in M. aeruginosa controlling, with the advantage of its cell morphology degrading ability.

In vivo antiviral efficacy of moroxydine hydrochloride against grass carp reovirus and the drug safety assessment

“…Both the C. vulgaris cultivation method and the concentration gradient assay of chemicals were identical to our previous study (Yu, Hao, et al, ). Three algae cultivated at 25°C under a 14:10‐hr photoperiod in sterile BG11 medium (Li and Hu, ).…”

“…C. idella , B. subtilis , C. vulgaris and T. thermophila are suitable non‐target toxicology materials used for the study. And different species have been demonstrated different sensitivity in response to chemicals (Ma, Zheng, Xu, & Wang, ; Yu, Hao, et al, ). The pharmacotherapy of grass carp haemorrhagic disease is becoming an important research of aquaculture industry and environmental water management due to lack of systematic evaluation for both the disease control and environmental safety problems.…”

“…However, the antiviral activity in vivo and the environmental toxicity of Mor remain unknown in aquatic ecosystems. The acute toxicity tests with fish and other representative organisms in aquatic systems have played a major role in drug safety assessments (Baker, Gilron, Chalmers, & Elphick, ; Yu, Hao, Ling, & Wang, ). Aquatic vegetation and algae are the primary producers of aquatic environment, keeping balance and stability of water ecological system, and directly or indirectly adjusting the structure and function of aquatic ecosystems (Ricardo, Virgile, & René, ; Zhang et al, ).…”

“…Bacillus subtilis has the ability to produce protease, lipase and amylase which enhances the water quality, growth performance, immune response and disease resistance in feed (Fisher, ; Zokaeifar et al, ). Therefore, it is frequently used to measure antimicrobial activity (Fang et al, ; Yu, Hao, et al, ). Tetrahymena thermophila as a freshwater ciliated protozoan is a predator of bacteria and prey on metazooplankton in aquatic food webs.…”

Functionalized Multi-Wall Carbon Nanotubes Enhance Transfection and Expression Efficiency of Plasmid DNA in Fish Cells

“…Ultrastructural changes of MWCNTs-NH 3 + /DNA complex incubated CIK cells are observed using scanning and transmission electron microscopy, respectively. The procedure for SEM and TEM sample were prepared as described previously [ 49 , 50 ]. Briefly, CIK cells were cultured in MEM medium contain 10% FBS in a 6-well plate at 28 °C in the present of 5% CO 2 until 90% confluency was reached.…”