Toxicity of Tetracycline and Metronidazole in Chlorella pyrenoidosa

Antibiotics have become a new kind of organic pollutant as they are widely used in the water environment of China. Tetracycline (TC) is a class of broad-spectrum antibiotics produced or semi-synthesized by actinomycetes. Metronidazole (MTZ) is the first generation of typical nitroimidazoles. The content of nitroimidazoles is relatively high in medical wastewater, and their ecotoxicity is worthy of attention because they are difficult to completely eliminate. In this paper, the effects of TC and MTZ on the growth, cell morphology, extracellular polymer and oxidative stress of Chlorella pyrenoidosa (C. pyrenoidosa) were studied, and the toxic interactions between TC and MTZ mixture components were analyzed. The results showed that the 96h-EC50 of TC and MTZ was 8.72 mg/L and 45.125 mg/L, respectively. The toxicity of TC to C. pyrenoidosa was higher than that of MTZ, and the combined toxicity effect of TC and MTZ was synergistic after the combined action of a 1:1 toxicity ratio. In addition, the algal cells of C. pyrenoidosa died to varying degrees, the membrane permeability of algal cells was increased, the membrane was damaged, the surface of algal cells exposed to higher concentration of pollutants was wrinkled, and their morphology was changed. The extracellular polymer of C. pyrenoidosa was affected by a change in concentration. The effect of pollutants on the reactive oxygen species (ROS) level and malondialdehyde (MDA) content of C. pyrenoidosa also had an obvious dose–effect relationship. This study contributes to the assessment of the possible ecological risks to green algae due to the presence of TC and MTZ in aquatic environments.

[1]  Yan Liang,et al.  Development of a whole-cell biosensor for detection of antibiotics targeting bacterial cell envelope in Bacillus subtilis , 2022, Applied Microbiology and Biotechnology.

[2]  Junwei Zhao,et al.  Ultrathin carbon-coated Zr3+-ZrO2 nanostructures for efficient visible light photocatalytic antibiotic elimination , 2021 .

[3]  Baolin Sun,et al.  VraCP regulates cell wall metabolism and antibiotic resistance in vancomycin-intermediate Staphylococcus aureus strain Mu50 , 2021, The Journal of antimicrobial chemotherapy.

[4]  C. Dong,et al.  Red fluorescent carbon dots for tetracycline antibiotics and pH discrimination from aggregation-induced emission mechanism , 2021 .

[5]  Zongyan Zhao,et al.  Construction of direct Z-scheme WO3/ZnS heterojunction to enhance the photocatalytic degradation of tetracycline antibiotic , 2021 .

[6]  G. Qiu,et al.  Insights into the production of extracellular polymeric substances of Cupriavidus pauculus 1490 under the stimulation of heavy metal ions , 2020, RSC advances.

[7]  Zhongxing Wu,et al.  The Effect of Bisphenol A on Growth, Morphology, Lipid Peroxidation, Antioxidant Enzyme Activity, and PS II in Cylindrospermopsis raciborskii and Scenedesmus quadricauda , 2018, Archives of Environmental Contamination and Toxicology.

[8]  H. Zheng,et al.  Comparative toxicity of the plasticizer dibutyl phthalate to two freshwater algae. , 2017, Aquatic toxicology.

[9]  Prasun Patra,et al.  Damage of lipopolysaccharides in outer cell membrane and production of ROS-mediated stress within bacteria makes nano zinc oxide a bactericidal agent , 2015, Applied Nanoscience.

[10]  Miao Li,et al.  Occurrences and regional distributions of 20 antibiotics in water bodies during groundwater recharge. , 2015, The Science of the total environment.

[11]  S. Antunes,et al.  Acute Effects of Tetracycline Exposure in the Freshwater Fish Gambusia holbrooki: Antioxidant Effects, Neurotoxicity and Histological Alterations , 2015, Archives of Environmental Contamination and Toxicology.

[12]  Jinping Cheng,et al.  Effects of tetracycline on developmental toxicity and molecular responses in zebrafish (Danio rerio) embryos , 2015, Ecotoxicology.

[13]  N. Chandrasekaran,et al.  Cytotoxicity of aluminium oxide nanoparticles towards fresh water algal isolate at low exposure concentrations. , 2013, Aquatic toxicology.

[14]  Yiping He,et al.  Antibacterial activities of magnesium oxide (MgO) nanoparticles against foodborne pathogens , 2011 .

[15]  I. Muñoz,et al.  Environmental and human health risk assessment of organic micro-pollutants occurring in a Spanish marine fish farm. , 2010, Environmental pollution.

[16]  Xiyun Cai,et al.  Enantioselective degradation and ecotoxicity of the chiral herbicide diclofop in three freshwater alga cultures. , 2008, Journal of agricultural and food chemistry.

[17]  S. Allakhverdiev,et al.  Molecular mechanisms of stress resistance of the photosynthetic apparatus , 2007, Biochemistry (Moscow) Supplement Series A: Membrane and Cell Biology.

[18]  David C. Stuckey,et al.  A REVIEW OF SOLUBLE MICROBIAL PRODUCTS (SMP) IN WASTEWATER TREATMENT SYSTEMS , 1999 .

[19]  P. Summanen,et al.  Activity of metronidazole and its hydroxy metabolite against clinical isolates of Actinobacillus actinomycetemcomitans. , 1988, Oral microbiology and immunology.

[20]  M L Richardson,et al.  The fate of pharmaceutical chemicals in the aquatic environment , 1985, The Journal of pharmacy and pharmacology.

[21]  P. Stepnowski,et al.  Determination of metronidazole residues in water, sediment and fish tissue samples. , 2015, Chemosphere.

[22]  Sharifah Najiha Badar,et al.  The current methods for the biomass production of the microalgae from wastewaters: an overview. , 2014 .

[23]  D. Barends,et al.  Biowaiver monographs for immediate release solid oral dosage forms: ciprofloxacin hydrochloride. , 2011, Journal of pharmaceutical sciences.

[24]  Monty Liong,et al.  Cationic polystyrene nanosphere toxicity depends on cell-specific endocytic and mitochondrial injury pathways. , 2008, ACS nano.

[25]  M. Dring.  Stress Resistance and Disease Resistance in Seaweeds: The Role of Reactive Oxygen Metabolism , 2005 .

[26]  S. B. Surman,et al.  CONSIDERATION OF SOME IMPLICATIONS OF THE RESISTANCE OF BIOFILMS TO BIOCIDES , 1998 .

[27]  E. Perkins.  Aquatic toxicology and hazard evaluation , 1979 .

[28]  Ll Marking.  Method for assessing additive toxicity of chemical mixtures , 1977 .