Plastic bioremediation potential of groundwater microbiomes

Global increase in the production of highly recalcitrant plastic materials and their accumulation in the environment are creating the urgent need to develop new sustainable strategies to mitigate this type of pollution. Microbial biotechnology, including blue biotechnology, is a promising option for the sustainable disposal of plastic waste. Despite both soil and water representing potential sources of novel biocatalysts, studies unraveling the biotechnological potential of soil microbial communities considerably outnumber studies of aquatic microbiota. Although traditionally focused on marine resources, the scope of blue biotechnology has expanded to include all aquatic ecosystems and the focus is shifting towards underexplored aquatic environments. Environmental niches that are not readily accessible for sampling, representing reservoirs of enzymatic activities with potential biotechnological applications, such as subsurface environments, especially its core component groundwater, are still relatively understudied. Despite a proposed overlap between microbial enzymatic capacity to degrade one of the substrates that has been available on Earth for a very long time—lignocellulosic biomass and a relatively newly available substrate, introduced only about a century ago by humans—plastics, studies investigating potential for the transformation of fossil and bio-based plastics by lignocellulose-degrading microorganisms and their consortia and bioprospecting for microorganisms capable of degrading both, are still relatively scarce. Here, we discuss and summarize recent advances in decoding plastolytic and lignocellulolytic potential of relatively rarely examined groundwater bacteria.