Beyond Visibility: Microorganisms for tackling plastic and microplastic problems for cleaner future

Globally, an overwhelming amount of plastic waste, approximately 400 million tons (Mt), is generated each year. The ocean plastic waste alone is expected to grow from 50 Mt in 2015 to 150 Mt by 2025, primarily due to poor waste management. Approximately 700 marine species interact with plastic debris, thriving in these threatened ecosystems. The challenge of plastic pollution, including microplastics and nanoplastics, is substantial. Plastics resist natural degradation due to their hydrophobic nature, stable covalent bonds, resistant functional groups, and large surface area that attracts other substances. Current efforts to tackle microplastics face significant challenges and require more mature and effective methods for widespread applications. Certain natural microorganisms can degrade plastics by 1) colonizing the surface, 2) producing exogenous enzymes to break-down polymers, and 3) metabolizing the resulting molecules. However, this process is still under research, with ongoing efforts to find the best natural and genetically modified microbes for more effective plastic degradation. Therefore, identifying the best microbe and efficient methods is crucial for reducing plastic pollution. This review summarizes the plastic problem, its types, accumulation, and natural degradation processes. It also examines current technologies and recently screened microorganisms for their potential to tackle plastics and microplastics for a cleaner future.