Microbial Depolymerization of Epoxy Resins: A Novel Approach to a Complex Challenge

Abstract

The objective of this project is evaluating the potential of microbes (fungi and bacteria) for the depolymerization of epoxy, aiming at the development of a circular management of natural resources for epoxy in a long-term prospective. For depolymerization, epoxy samples were incubated for 1, 3, 6 and 9 months in soil microcosms inoculated with Ganoderma adspersum. Contact angle data revealed a reduction in the hydrophobicity induced by the fungus. Environmental scanning electron microscopy on epoxy samples incubated for more than 3 years in microbiological water revealed abundant microbiota. This comprised microbes of different sizes and shapes. The fungi Trichoderma harzianum and Aspergillus calidoustus, as well as the bacteria Variovorax sp. and Methyloversatilis discipulorum, were isolated from this environment. Altogether, these results suggest that microbes are able to colonize epoxy surfaces and, most probably, also partially depolymerize them. This could open promising opportunities for the study of new metabolisms potentially able depolymerize epoxy materials.

Inoculation Effect of Methanotrophs on Rhizoremediation Performance and Methane Emission in Diesel-Contaminated Soil

“…Methyloversatilis spp. had been isolated from lake sediment, biofilm on steel-bentonite interphase, and so on [ 32 , 33 ].…”

Towards Sustainable Recycling of Epoxy-Based Polymers: Approaches and Challenges of Epoxy Biodegradation

“…The authors were able to visualize the increase of surface roughness of the resin droplets as a result of microbial attack. ESEM was also employed in experiments from Pardi-Comensoli et al [ 89 ], who screened cured epoxy samples for attached microorganisms after incubation in microbiological water. The morphological inspection of the surfaces facilitated the identification of the types of microorganisms interacting with the epoxy and revealed similar crystal depositions as described earlier.…”

“…The application of contact angle measurement for epoxy degradation analysis was conducted by Pardi-Comensoli et al [ 89 ]. They used a goniometer to measure the contact angle of water droplets on the epoxy resin samples before and after soil incubation.…”

“…Exploiting the chemical similarities of lignin to cured epoxy, Pardi-Comensoli et al [ 89 ] approached the epoxy degradation by utilizing Ganoderma adspersum , a fungus known to produce lignin peroxidase and laccase. As these two enzymes are predominantly involved in lignin degradation, it was also assumed, that they would act on epoxy.…”