Impact of erythromycin on a non-target organism: Cellular effects on the freshwater microalga Pseudokirchneriella subcapitata

Abstract

The increasing and indiscriminate use of antibiotics is the origin of their introduction in aquatic systems through domestic and livestock effluents. The occurrence of erythromycin (ERY), a macrolide antibiotic, in water bodies raises serious concerns about its potential toxic effect in aquatic biota (non-target organisms), particularly in microalgae, the first organisms in contact with aquatic contaminants. This study aimed to evaluate the possible toxic effects of ERY on relevant cell targets of the freshwater microalga Pseudokirchneriella subcapitata. Algal cells incubated with significant environmental ERY concentrations presented disturbance of the photosynthetic apparatus (increased algal autofluorescence and reduction of chlorophyll a content) and mitochondrial function (hyperpolarization of mitochondrial membrane). These perturbations can apparently be attributed to the similarity of the translational machinery of these organelles (chloroplasts and mitochondria) with the prokaryotic cells. P. subcapitata cells treated with ERY showed a modification of metabolic activity (increased esterase activity) and redox state (alteration of intracellular levels of reactive oxygen species and reduced glutathione content) and an increased biovolume. ERY induced an algistatic effect: reduction of growth rate without loss of cell viability (plasma membrane integrity). The present study shows that chronic exposure (72 h), at low (μg L −1) ERY concentrations (within the range of concentrations detected in surface and ground waters), induce disturbances in the physiological state of the alga P. subcapitata. Additionally, this work alerts to the possible negative impact of the uncontrolled use of ERY on the aquatic systems.

Reproductive cycle progression arrest and modification of cell morphology (shape and biovolume) in the alga Pseudokirchneriella subcapitata exposed to metolachlor

“…The influence of MET in FDA hydrolysis or fluorescein fluorescence was evaluated. For this purpose, abiotic controls (without cells) with different concentrations of MET and FDA or fluorescein were also performed as previously reported (Machado and Soares, 2019b).…”

Integral Valorization of Two-Phase Olive Mill Solid Waste (OMSW) and Related Washing Waters by Anaerobic Co-digestion of OMSW and the Microalga Raphidocelis subcapitata Cultivated in These Effluents

“…The line slope led to a value of μ max = 0.31 ± 0.02 day −1 . On the other hand, g or the generation time or doubling population time (day) 35 was estimated by eq 3.…”

“…The line slope led to a value of μ max = 0.31 ± 0.02 day –1 . On the other hand, g or the generation time or doubling population time (day) was estimated by eq . Considering the value of μ max and according to eq , the generation time was 2.23 days.…”

The Toxic Effects of Antibiotics on Freshwater and Marine Photosynthetic Microorganisms: State of the Art

“…Presumably, the most sensitive and primary site of inhibition caused by environmental pollution is photosystem II-an enzyme complex located in the thylakoid membrane in cyanobacteria and algae [41]. Many studies have demonstrated the reduced photosynthetic efficiency and pigment content as a result of antibiotic exposure [42,43]. Previous research showed that some antibiotics inhibit chlorophyll synthesis by interfering with gene expression of the chloroplast, thus disrupting the physiological process of photochemical reactions [44].…”