Insightful analysis of cyanobacterial-assisted degradation of different polymers and their kinetics

• Published in: Algal research (Amsterdam) 2024-07, Vol.81, p.103565, Article 103565
• Main Authors: Sarkhel, Rwiddhi, Bhunia, Biswanath, Gupta, Parthapratim, Mandal, Tamal
• Format: Article
• Language: English
• Subjects: Bioremediation; Contaminants; Degradation; Environment; Polymers
• ISSN: 2211-9264; 2211-9264
• DOI: 10.1016/j.algal.2024.103565

The usage of plastics has increased reliably over the years. Worldwide plastic pollution has grown to 460 million tons annually, increasing global greenhouse gas emissions by 3.4 %. In recent years, several studies have been performed utilizing microorganisms for bioremediation. The aggregation of microplastics affects marine aquatic life, posing a severe threat to the aquatic environment and hurting the global food chain. Bioremediation of various polymers is cost-effective and environmentally feasible compared to chemical, physical, and biophysical methods. Cyanobacteria, also known as blue-green algae, are photosynthetic organisms and can generate value-added products from waste, i.e., waste valorization and minimization. The present study uses Cyanobacterial sp. (Anabaena & Nostoc) to degrade the synthetic polymers prepared in lab-scale conditions. Weight loss of the degraded polymers was examined, and polymeric characteristics were analyzed through SEM, FTIR, XRD, and AFM. The experimental study observed that the polymers degraded by about 70 % and 82 % by Nostoc and Anabaena sp. in about eight weeks (approx. Two months). Polymers are degraded into monomers such as vinyl alcohol, ethylene, terephthalic acid, polycaprolactone from polyethylene terephthalate, and polyvinyl alcohol. They further break down into carbon dioxide, hydrogen, and water. These are identified from the LCMS-MS analysis. The experimental data for the degradation of polymers in Cyanobacteria sp. and control media fitted the Sinclair and Peppas kinetic model well. The results inferred that those cyanobacteria could degrade the polymers very effectively since it is a potent bioremediatory agent that can remove different organic and inorganic contaminants from the environment. [Display omitted] •Emphasize the degradation efficiency of polymer and polymer composites by cyanobacteria, reducing marine litter pollution.•Interaction between cyanoenzymes and polymer-polymer composites triggers the biodegradation treatment.•Influence of various process parameters on the rate of degradation of polymer.•Polymer kinetics were represented as a pathway for bioremediation technologies.