Bibliometric analysis of publications on biodegradation of plastics: Explosively emerging research over 70 years

Due to the environmental persistence and ecotoxological impacts of plastic waste and debris, pollution as the result of micro- and nano-plastics is a global concern. Here we provide a comprehensive review of both the history of research into the biodegradation of plastics as well as future trends in this area. A systematic literature search and review was carried out via Google Scholar by using predefined criteria to define a compilation of sources from January 1960 to May 2023, which indicated that research on plastics degradation has increased explosively since 1991. After a primary search, bibiometric analysis was employed using the Web of Science Core Collection's (WoSCC) of online databases to provide an additional core of 1500 significant original articles on biodegradation of petroleum-based synthetic plastics from January 1991 to May 2023. Studies on biodeterioration and biodegradation of petroleum-derived plastics were first conducted in the mid-1960s, with a focus on polyvinyl chloride. Soon, all major plastics were found to be extremely persistent to biodegradation. Research altered to develop biodegradable plastics. In the 1990s, microbial degradation of polyethylene plastics and enzymatic degradation of polyethylene terethphalate were confirmed and research accelerated rapidly. The discovery of plastics-degrading enzymes from bacteria and fungi and rapid biodegradation of all major plastics in some insect gut on an hourly basis opened the door to solve plastics pollution. Using the bibliometric tool Cite Space, we analyzed collaborative mapping domains, top researchers, hot research areas, and trends on plastic biodegradation with the aim of gaining a thorough understanding of current research trends. A current focus in research is enzyme-mediated biodegradation of plastics by microorganisms (fungi, bacteria, etc.) and insects. Plastics biodegradation associated with microbiome, metabolome, proteome and transcriptome of environmental microbes, gut microbes, and host insects will lead future research perspectives.