LONDON (CWBN)_ A miraculous new biodegradable plastic that deteriorates in seawater has been developed by The OXOMAR Project that is expected to revolutionise the critical issue of plastic pollution around the globe.
The OXOMAR Project funded by the French National Research Agency (ANR) in collaboration with four independent CNEP, LOMIC, ICCF, and IFREMER has come out with an environment-friendly Oxo-biodegradable plastics with zero toxicity that could potentially solve the plastic waste at sea.
The objective of the ANR-OXOMAR project, which was commenced in 2016, was to find out, whether Oxo-biodegradable plastics will fully biodegrade in a reasonable time in the marine environment, and to make sure that Oxo-biodegradable plastic or its by-products would create any toxicity in the marine environment, harming the marine lives.
Biodegradability of plastics
Biodegradability of plastics is the ability to break down plastics into simpler substances that can be totally converted by microbial activity into microbial biomass, water, and CO2. Oxo-biodegradable plastics (OXO) are made from conventional polymers such as polyethylene (PE) or polypropylene (PP) with the addition of a prodegradant catalyst (often a salt of manganese or iron) that catalyses the abiotic oxidation process, which reduces the molecular weight and enables biodegradation.
The project has yielded congruent results from multidisciplinary approach that clearly shows that Oxo-biodegradable plastics biodegrade in seawater with a higher degree of efficiency compared to conventional plastics. The oxidation level obtained due to the d2w prodegradant catalyst was found to be of crucial importance in the degradation process. Out of the six-formulations tested, the Mn/Fe pro-oxidant was the most efficient, with no toxic effects under our experimental conditions. Biodegradability was demonstrated either by using the culture bacteria Rhodococcus rhodochrous or by a complex natural marine community of microorganisms.
The team of researchers also successfully developed labelled 13C-OXO that will allow the team to trace the incorporation of carbon into the cells and to follow its complete mineralisation into CO2, in order to provide further understanding of the process.
The OXOMAR project has used a large set of high-level and complementary methodologies, including the most recent advances such as Artificial Ageing, one of the key process to accelerate the abiotic degradation by using UV and temperature, and specific equipment (Bandol wheel or SEPAP). These technologies were designed for this project to ensure a better simulation of the marine environment.
Another groundbreaking technologies that were used were the new analytical methods in chemistry that also developed (High Resolution Mass Spectrometry and NMR spectroscopy) to characterise the by-products of the degradation, namely the ‘oligomers’. They are proofs of biodegradability in the transition step between the initial polymers and the monomers that will be ingested and biodegraded by microorganisms to be finally transformed into CO2.
Advanced technologies in the field of Microbiology such as Respirometry, Metagenomic, Metabolomic, DNA-stable isotope probing were also employed to better evaluate the biodegradation process, taking into account the large biodiversity of microorganisms living on plastics, the so-called ‘plastisphere’.
A large set of marine organisms with different sensibility to pollutants (including sea urchin, sea bass, amphioxus, oyster, and bacteria) as bioindicators were used to establish the absence of potential toxic elements from the original polymer and from by-products.
The OXOMAR Project was carried out under the guidance and supervision of Dr Jean-François Ghiglione. He is the director of research for the French national center of scientific research (CNRS) at the Laboratoire d’Océanographie Microbienne since 2001. He is the head of the team “Marine microbial ecotoxicology and engineering” and the co-founder of the start-up Plastic@Sea. He is co-manager of the French network “GDR 2050 Polymeres & Oceans” and member of the scientific committee of BeMed business club. He coordinated 15 national and international projects and he published 76 scientific articles in peer-review journals (h-index 30). He dispensed 41 conferences for general audience and he was interviewed for 122 press articles and 71 Radio/TV reportages.
Edited by Indeewara Thilakarathne
