Response of Spirulina Platensis to Sulfamethazine Contamination

The interaction between a positive important biological energy source algae Spirulina platensis and an antimicrobial drug sulfamethazine was studied by a panel of bioassays. The result demonstrated that the acute toxicity of sulfadimidine on Spirulina platensis gradually increased with the increasing of the concentration of sulfadimidine. During the exposure, the toxicity of sulfamethazine on Spirulina platensis enlarged at first and reduced thereafter, and the summit was at 48 h, showing a typical "bell" curve. The EC₅₀ in 48 h was 6.06 mg/L. Spirulina platensis was able to accumulate and degrade sulfamethazine simultaneously. The amounts of sulfamethazine accumulated and degraded by Spirulina platensis were 1.40 mg/kg and 0.64 mg/kg (dry weight) at 24 h, respectively. After 96 h of exposure, the accumulation decreased to 0.47 mg/kg, however, the degradation of sulfamethazine increased to 6.57 mg/kg. Due to biological activity, the removal rate of sulfamethazine was 5.2 times in the nutrient solution with Spirulina platensis as that of without Spirulina platensis. The results of this study implied that Spirulina platensis had a potential to remove sulfamethazine in the sulfamethazine contaminated aquatic ecosystems.