Bioremediation of PET Pollution Using Microorganisms Active at Moderate Temperatures
TL;DR
The potential of utilizing the Ideonella sakaiensis system that was discovered a decade ago, and PET-degrading enzymes encoded by this bacterium, are able to operate at moderate temperatures, unlike most other enzymes being developed to provide bioremediation of PET pollution.
Abstract
Plastics such as polyethylene terephthalate (PET) are widely used worldwide because they are inexpensive, versatile, and suitable for numerous applications. However, most products made of PET are designed for single use, and the resulting waste is chemically inert and highly resistant to microbial degradation. Consequently, PET accumulation has become a major source of environmental pollution and poses serious threats to ecosystems. Biorecycling and bioupcycling have emerged as some of the most promising strategies for reducing PET pollution. For macro-scale PET waste, industrial approaches are being developed, including those pursued by the French company Carbios, although significant technical and economic challenges remain. In contrast, for micro- and nanosized PET particles, commonly referred to as microplastics, no large-scale remediation systems have been implemented yet. Here we highlight the potential applications of microorganisms and their enzymes for remediation of microplastic pollution, especially because these systems can function at moderate temperatures, in contrast to high-temperature industrial processes. In particular, we highlight the potential of utilizing the Ideonella sakaiensis system that was discovered a decade ago. PET-degrading enzymes encoded by this bacterium, such as IsPETase and IsMHEtase, are able to operate at moderate temperatures, unlike most other enzymes being developed to provide bioremediation of PET pollution.