Understanding Marine Biodegradation of Bio-Based Oligoesters and Plasticizers

Abstract: The study reports the enzymatic synthesis of bio-based oligoesters and chemo-enzymatic
processes for obtaining epoxidized bioplasticizers and biolubricants starting from cardoon seed oil.
All of the molecules had MW below 1000 g mol􀀀1 and were analyzed in terms of marine biodegradation.
The data shed light on the effects of the chemical structure, chemical bond lability, thermal
behavior, and water solubility on biodegradation. Moreover, the analysis of the biodegradation
of the building blocks that constituted the different bio-based products allowed us to distinguish
between different chemical and physicochemical factors. These hints are of major importance for the
rational eco-design of new benign bio-based products. Overall, the high lability of ester bonds was
confirmed, along with the negligible effect of the presence of epoxy rings on triglyceride structures.
The biodegradation data clearly indicated that the monomers/building blocks undergo a much
slower process of abiotic or biotic transformations, potentially leading to accumulation. Therefore,
the simple analysis of the erosion, hydrolysis, or visual/chemical disappearance of the chemical
products or plastic is not sufficient, but ecotoxicity studies on the effects of such small molecules are
of major importance. The use of natural feedstocks, such as vegetable seed oils and their derivatives,
allows the minimization of these risks, because microorganisms have evolved enzymes and metabolic
pathways for processing such natural molecules.