Blue technology for a sustainable pharmaceutical industry: Microalgae for bioremediation and pharmaceutical production

A microalgae biorefinery is an industrial facility where microalgae biomass is cultivated and fractionated to produce raw materials for use in various fields. The pharmaceutical industry can be part of a microalgae biorefinery through drug bioremediation, extraction, and use of biologically active compounds and excipients. The objective of this work was to review progress in the removal of pharmaceuticals by microalgae and to highlight the implications for microalgal growth, subsequent biomass utilization, health promotion, and raw material production. The studies, published between 2011 and 2020, used a variety of microalgae, most of which belong to the genera Chlorella and Scenedesmus. Classes of active ingredients of particular concern, such as nonsteroidal anti-inflammatory drugs, antibiotics, and estrogens, were removed. The various microalgae were able to grow in the presence of pharmaceuticals in water and wastewater. The removal achieved by the microalgae was comparable to that achieved by conventional wastewater treatment. Removal by microalgae appears to occur mainly by biodegradation or biotransformation processes, with biosorption and bioaccumulation playing a minor role. Currently, the removal of pharmaceuticals by microalgae in wastewater is a secondary treatment. However, metabolic analysis is needed to accurately determine the mechanisms of pharmaceuticals' biodegradation by the various microalgae. Therefore, the next generation of studies should consider expanding the pharmaceuticals tested, evaluate the combined effect of different microalgae, and pay more attention to raw material production, biomass utilization, and purification mechanisms.

Automated summary

A microalgae biorefinery is an industrial facility that cultivates and fractionates microalgae biomass to produce raw materials. The pharmaceutical industry can be involved in a microalgae biorefinery through drug bioremediation and the use of active compounds. This study reviewed the progress in pharmaceutical removal by microalgae and emphasized its implications for biomass utilization, health promotion, and raw material production. Various microalgae were able to grow in the presence of pharmaceuticals and achieved comparable removal to conventional wastewater treatment. The removal mainly occurred through biodegradation or biotransformation processes.