Stimulation effects of ciprofloxacin and sulphamethoxazole in Microcystis aeruginosa and isobaric tag for relative and absolute quantitation‐based screening of antibiotic targets

Abstract

Antibiotics are normally regarded as safe to aquatic ecosystems when their contamination concentrations are lower than the toxic threshold. This study observed the hazard of ciprofloxacin, sulphamethoxazole and their binary mixture to the aquatic environment at environmentally relevant concentrations lower than the toxic threshold, due to the stimulation on the bloom of Microcystis aeruginosa. The enhanced growth of M. aeruginosa, coupled with elevated photosynthesis activity, was exerted by 50-200 ng/L of ciprofloxacin, 100-200 ng/L of sulphamethoxazole and 20-100 ng/L of the binary antibiotic mixture. Stimulated production and release of microcystins were observed at even lower concentrations. The upregulation of transcription-related proteins, cell division-related proteins, a gas vesicle protein, a global nitrogen regulator (ntcA), two microcystin synthetases (mcyC and mcyH) and ATP-binding cassette transporters provided direct proteomic evidence for the regulation of target antibiotics on M. aeruginosa bloom. Cytochrome P450 was an essential component involved in stress responses and antibiotic biodegradation. Proteomic responses to antibiotic exposure presented a shift in the energy metabolism of M. aeruginosa towards the excitation of photosynthesis, an increase of carbohydrate biosynthesis and the inhibition of carbohydrate catabolism. Superoxide dismutase, enolase and D1 protein were candidate target proteins of different antibiotics in M. aeruginosa. The antibiotic mixture showed a greater hazard than single antibiotics, and a safe threshold of 5 ng/L was suggested for each target antibiotic under the coexistence condition.

Effect of PHRs and PCPs on Microalgal Growth, Metabolism and Microalgae-Based Bioremediation Processes: A Review

“…In another study, amoxicillin at 200–500 ng/L did not alter or slightly enhanced the growth of Microcystis aeruginosa , and the stimulatory effect was correlated with the increase in N concentration (from 0.05 to 5 mg/L) in the growth medium [211]. Moreover, growth of Microcystis aeruginosa was improved by up to 33% in the presence of 50–200 ng/L of ciprofloxacin [212] and by up to 25% in the presence of 100–200 ng/L of sulphamethoxazole [212]. Interestingly, the cyanobacterium Phormidium valderianum was able to utilize ampicillin as a nitrogen source via extracellular production of β-lactamase, the enzyme that breaks a β-lactam ring [213].…”

Influence of mixed antibiotics on Microcystis aeruginosa during the application of glyphosate and hydrogen peroxide algaecides

“…However, four of the target antibiotics, amoxicillin, spiramycin, ciprofloxacin, and sulfamethoxazole, were indicated to regulate the expression of ATP‐binding cassette transporters and facilitate the export/secretion of cellular and exogenous substances (Liu et al. ). The presence of coexisting antibiotics may promote the secretion of H 2 O 2 and glyphosate from cyanobacterial cells and alleviate stress in the antioxidant system.…”

“…For instance, 100 lg Á L À1 ofloxacin was found to increase the chlorophyll a content and the photosynthetic activity of Microcystis aeruginosa (Deng et al 2015). In addition, 0.001-0.1 lg Á L À1 erythromycin was observed to stimulate the growth and photosynthetic activity of Microcystis flos-aquae (Wan et al 2015, Liu et al 2017. Previous studies by our group found that spiramycin, amoxicillin, ciprofloxacin, and sulfamethoxazole each stimulated the photosynthesis, growth, and production of microcystins (MCs) in M. aeruginosa (Liu et al , 2017.…”

“…, Liu et al. ). Previous studies by our group found that spiramycin, amoxicillin, ciprofloxacin, and sulfamethoxazole each stimulated the photosynthesis, growth, and production of microcystins (MCs) in M. aeruginosa (Liu et al.…”

“…Previous studies by our group found that spiramycin, amoxicillin, ciprofloxacin, and sulfamethoxazole each stimulated the photosynthesis, growth, and production of microcystins (MCs) in M. aeruginosa (Liu et al. , ). The stimulatory effects of antibiotics may alleviate the toxicity of algaecides in cyanobacteria and should be taken into account during the utilization of algaecides.…”