The interplay between bisphenol A and algae – A review

Bisphenol A (BPA) is a synthetic organic compound used as raw material in many industrial products, particularly epoxy resins and polycarbonate plastics. Due to its extensive applications, increasing contamination in the environment and adverse effects on living organisms, BPA has been regarded as a pollutant of emerging concern. In aquatic environments, it has been detected ubiquitously in concentrations ranging from few ng L−1 to several µg L−1. BPA has been found toxic to a number of aquatic organisms from diverse taxa at all trophic levels. In terms of photosynthetic organisms, a complex interplay occurs between BPA and algae. BPA adversely affects algae by inhibiting several physiological and biochemical processes; at the same time, algae potentially biodegrade and/or remediate the environmental BPA. In this review article these complex interactions between algae and BPA are elaborated. The effects of BPA on different parameters of algae including growth, light-harvesting pigments, photosynthesis, respiration, morphology and macromolecules are discussed. Considering the reported EC50/IC50 values of BPA for algae growth and following the criteria of the EU-Directive 93/67/EEC for classifying aquatic pollutants, BPA can be classified as toxic and harmful to algae (having EC50 in the range of 1–10 and 10–100 mg L−1). The oxidative stress caused by BPA resulting in lipids peroxidation of cellular membranes is the most possible cause of BPA toxicity in algae. In addition, the abilities of different algae to remove BPA by adsorption, accumulation and biodegradation are also compared and discussed. Algae remove BPA from water mainly by biodegrading it with monohydroxy-BPA and BPA-glycosides as the most common intermediates. Algae generally remove BPA more efficiently at low doses of BPA (lower than 1 mg L−1) but increase in the concentration of BPA greatly reduces the biodegradation efficiency of algae. For an in-depth understanding, the molecular responses of algae to BPA exposure are reviewed. This manuscript provides comprehensive information on the subject matter that would be useful for both academia and policy makers working in this domain.