Bioremediation of Microplastics by Cyanobacteria

A high amount of plastic accumulation has been taking place throughout the world since the 1950s due to massive plastic and microplastics production. Plastic debris thrown into the environment is a point of concern. These microplastics pollute the environment and cause a hazard to human health and the environment. The agglomeration of microplastics affects marine aquatic life, posing a serious threat to flora and fauna causing a negative effect on the global food chain. Bioremediation of plastics as well as microplastics are very cost-effective and environmentally feasible but time-consuming. Cyanobacteria, also known as blue-green algae, are photosynthetic organisms and can generate value-added products from waste, i.e., waste valorization and minimization. In the present study, Cyanobacterial sp. (Anabaena and Nostoc) have been utilized to degrade the microplastics collected from nearby rivers and lakes. Some plastics have also been collected from the non-biodegradable waste plastic bottles thrown here and there. But due to their immense ability, cyanobacteria sp. can degrade the waste plastics very effectively. It has been interpreted from the study that cyanobacteria can grow best at alkaline pH, room temperature, with enough light intensity at about 5 lux and agitation not required. They degrade 70% following these optimal conditions. They also generate an algal bloom, producing value-added products. Therefore, it can be said that the bioremediation process by the blue-green algae seems to be a promising alternative for the sustainability of the environment.