Paper Title
Physicochemical Properties of Non-Biodegradable and Biodegradable Plastic Wastes on Biofilm Formation

Abstract
Biofilm formation becomes a great environmental concern that enhance the adverse effects of plastic waste in the ecosystems. To date, there are many evidences that plastic wastes served habitable area for natural microbes, but how these bacteria attached to plastic waste are poorly understood. In this study, Escherichia coli k12 which were used as pathogenic representative were investigated the attachment on four types of plastic wastes, including polypropylene, polyethylene, polyvinyl chloride and polylactic acid, which are frequently encountered in the aquatic environment for two months. The result showed that with increased incubation time, planktonic cell can switch into bacterial community to adhere on all type of plastic and form biofilm increasingly. Differences in nutrient sources also govern bacterial colonization. Submerged plastic in seawater were found the attached bacteria into clumped shape since 2nd weeks more than other plastic sheets. In addition, physicochemical measurement on plastic demonstrated that polyethylene showed the highest hydrophilicity with the ability of biofilm formation. However, change of physicochemical of plastics occurred in all plastics due to the increase of biofilm; plastic sheets trend to reduce hydrophobicity from their nature. Hence, environmental conditions, duration time and less hydrophobicity characteristics have potential to influence the ability of E.coli to form biofilm on plastic wastes. Keywords - Biofilm, Plastic Wastes, Hydrophobicity