Marine Environmental Plastic Pollution: Mitigation by Microorganism Degradation and Recycling Valorization

Juliana Oliveira,Ana Rotter,Afonso Belchior,Nídia D Lourenço,Susana P Gaudêncio,Verônica D Da Silva,Željko Petrovski,Pedro L Almeida

doi:10.3389/fmars.2020.567126

Abstract

Plastics are very useful materials and present numerous advantages in the daily life of individuals and society. However, plastics are accumulating in the environment and due to their low biodegradability rate, this problem will persist for centuries. Until recently, oceans were treated as places to dispose of litter, thus the persistent substances are causing serious pollution issues. Plastic and microplastic waste has a negative environmental, social, and economic impact, e.g., causing injury/death to marine organisms and entering the food chain, which leads to health problems. The development of solutions and methods to mitigate marine (micro)plastic pollution is in high demand. There is a knowledge gap in this field, reason why research on this thematic is increasing. Recent studies reported the biodegradation of some types of polymers using different bacteria, biofilm forming bacteria, bacterial consortia, and fungi. Biodegradation is influenced by several factors, from the type of microorganism to the type of polymers, their physicochemical properties, and the environment conditions (e.g., temperature, pH, UV radiation). Currently, green environmentally friendly alternatives to plastic made from renewable feedstocks are starting to enter the market. This review covers the period from 1964 to April 2020 and comprehensively gathers investigation on marine plastic and microplastic pollution, negative consequences of plastic use, and bioplastic production. It lists the most useful methods for plastic degradation and recycling valorization, including degradation mediated by microorganisms (biodegradation) and the methods used to detect and analyze the biodegradation.

Highlights

One of the main consequences of the models and patterns of production and consumption adopted by today’s society is the generation of waste, a major environmental problem that is increasingly demanding attention to the search for solutions, especially with regard to marine pollution (Savelli et al, 2017; Walker, 2018; Wysocki and Billon, 2019)
We suggest a combination of two processes, e.g., chemical recycling and biodegradation, to improve the total outcome and eliminate or at least reduce some of the non-commercial waste products
Microorganisms are capable of degrading plastics/microplastics as well as producing bioplastics

Summary

Introduction

One of the main consequences of the models and patterns of production and consumption adopted by today’s society is the generation of waste, a major environmental problem that is increasingly demanding attention to the search for solutions, especially with regard to marine pollution (Savelli et al, 2017; Walker, 2018; Wysocki and Billon, 2019). Despite decades of efforts to prevent and reduce marine litter in many countries, there is evidence that the problem is persistent and continues to increase, as human populations and single-use consumption patterns continue to rise. Due to the low rate of degradation, plastics remain in the marine ecosystem for long periods (Hopewell et al, 2009). These residues tend to accumulate in certain locations, due to oceans waves, currents, and winds, and can be found even in remote areas (GESAMP, 2015; Sebille et al, 2020). In coastal areas, where human activities are concentrated, the problem of increasing plastic pollution becomes even more apparent (Barnes et al, 2009; Ho and Not, 2019)

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