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| Author(s): |
Kethlen Rose Inacio da Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2009-01-29 |
| Examining board members: |
Lúcia Regina Durrant;
Cristiano Ragagnin de Menezes;
Rose Marry de Araujo Gondim Tomaz
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| Advisor: | Lúcia Regina Durrant |
| Abstract | |
In 1977, polyethylene terephthalate (PET), a plastic derived from petroleum, started to be used as raw material for packaging material and engineering plastics. However, under an environmental point of view, the use of plastics is considered problematic because of their high durability and high volume when present in domestic and industrial solid wastes. This study investigated the biodegradability of synthetic polymers by white-rot basidiomycete fungi cultivated on agro industrial residues under two fermentation conditions, semi-solid state and submerged fermentation. Two Pleurotus strains were grown in agro-industrial residues with either PET pellets or squares of transparent PET¿s bottles under semi-solid and submerged fermentation and incubated at 30 C for 30, 60 and 90 days. After incubation, the material obtained following filtration of samples and polymers were analyzed for determination of enzymatic activities, production of biosurfactants, mass loss, modifications on the morphology of the polymer, intrinsic viscosity and determination of the rate of degradation. Pleurotus 001 showed the best results when incubated with pellets, showing changes in the structure of the polymer, weight loss and reduction of intrinsic viscosity, production of biosurfactants, and of lignocellulolytic enzymes and a low respiratory activity. These results show that ligninolytic fungi can help improve the degradation of synthetic materials. However, further studies to determine the optimum conditions for growth of these fungi associated with combinations of physical and chemical treatment to maximize the degradation process are still necessary (AU) | |