Intelligent Technologies, Enzyme-Embedded and Microbial Degradation of Agricultural Plastics

Abstract

This review appraised current research on enzyme-embedded biodegradable agricultural plastics and microbial degradation, given that the increased use of fossil-fuel-based plastics in agriculture involved significant environmental tradeoffs. Over 370 million tons of plastics were produced in 2019, releasing over 400 million tons of greenhouse gases during production, transportation, consumption, burning, and exposure to sunlight biodegradation. Less than 10% of bags are recycled at the end of their life, leading to environmental pollution. Thus, it is imperative to summarize studies that have suggested solutions of this problem. The scoping review approach was preferred, given that it established current practices and uncovered international evidence on bio-based solutions and conflicting outcomes. Bioplastics with low greenhouse warming potential had a small market share (approximately 1%). The accumulation of fossil-fuel-based plastics and poor post-use management releases mercury, dioxins, furans, and polychlorinated biphenyls (PCBs). Enzyme-embedded polymers degrade fast in the environment but lack the desired mechanical properties. Even though polylactic acid (PLA) and other bioplastics are better alternatives to synthetic polymers, they persist in the environment for years. Fast degradation is only practical under special conditions (elevated temperatures and humidity), limiting bioplastics’ practical benefits. The research and development of plastics that could degrade under ambient conditions through enzyme-catalyzed reactions and soil-inoculated microbes are ongoing. However, there are no guarantees that the technology would be profitable in commercial agriculture. Other limiting factors include the geographical disparities in agricultural plastic waste management. Future perspectives on the waste management of agricultural plastics require smart technologies, such as artificial intelligence (AI), machine learning (ML), and enzyme-embedded plastics that degrade under ambient conditions. The replacement of synthetic plastics with polylactic acid and polycaprolactone/Amano lipase (PCL/AL) composite films would offset the negative ecological effects. A major drawback was the slow research and development and commercial adoption of bio-based plastics. The transition to bioplastics was resource- and time-intensive.