from the conferences organized by TANGER Ltd.
Plastic waste has been a growing threat to the environment and society. As most plastics are made from petroleum, eco-friendlier material, named bio-based plastics, made fully or partially from renewable sources, have been introduced and expected to be more biodegradable. However, their biodegradation and fate in the environment are not fully understood. Here, we studied the initial phase of plastic biodegradation, which was an attachment of freshwater microalga Raphidocelis subcapitata, on three types of starch-based bio-compostable plastic bags with the main component of polyethylene terephthalate (PET). PET-C was made from corn starch, PET-CB made from cornstarch and beetroot, and PET-CPW made from corn, potato and wheat starch. The plastic pieces (1 x 1 cm2) were added into the algal culture and incubated at laboratory temperature with low light density. The algal attachment and growth were then monitored and the changes of plastic properties were analyzed by a scanning electron microscope (SEM) for morphology, a confocal microscope (CM) for surface roughness and a contact angle for hydrophobicity. After the first week, algal cells were already attached on the plastic surface and formed colonies. The highest cell density was found in samples with PET-CPW following by PET-C and PET-CB. The surface morphology and surface roughness changed to be less rough, and the hydrophobicity of the plastics was lower.
Keywords: Raphidocelis subcapitata, PET, bio-based plastics© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.