Utilização do óleo residual de fritura na produção de polihidroxialcanoatos
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Data
2017-07-31
Autores
Rocha, Ligia Linardi Niero [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Os polihidroxialcanoatos (PHAs) são uma família de biopolímeros biodegradáveis, que podem substituir os plásticos petroquímicos em muitas aplicações, principalmente embalagens e utensílios domésticos. Contudo, estes bioplásticos são atualmente mais caros do que os de origem petroquímica. É possível encontrar vários estudos na literatura que investigam o uso de resíduos e substratos mais baratos, com o intuito de permitir a produção em grande escala do PHA. Os óleos vegetais são largamente utilizados na preparação de alimentos, na maioria das vezes no processo de fritura, o que acarreta grandes quantidades de resíduo, muitas vezes descartados incorretamente, trazendo prejuízo ao meio ambiente e à população. Sob esta consideração, os resíduos de óleo de fritura são abundantes e podem ser utilizados na produção de PHA sem qualquer tratamento adicional. Portanto, este trabalho analisou a produção de polihidroxialcanoatos (PHA) a partir de duas linhagens de bactérias, Pseudomonas oleovorans e Bacillus megaterium, utilizando-se óleos residuais de frituras como fonte de carbono (óleo residual de fritura de batata, frango e pastel) e foram utilizados nas concentrações de 10 g.l-1 e 20 g.l-1, separadamente. Os ensaios de produção do biopolímero foram realizados em frascos agitados, em meio de cultura limitante em nitrogênio. A massa seca celular (MSC) foi determinada por gravimetria e a porcentagem de acúmulo e a composição do PHA foram determinados por cromatografia gasosa. A melhor condição de reação foi observada no óleo residual de fritura de batata, no qual a bactéria Bacillus megaterium alcançou uma concentração de 13,03 % de acúmulo de PHA (% MSC) e 3,93 g.l-1 de massa seca celular. Pelos resultados obtidos pode-se concluir que esta alternativa é promissora, além de não competir com a produção baseada em fontes de açúcar, que é comercialmente utilizada.
Polyhydroxyalkanoates (PHAs) are a family of biodegradable biopolymers that can replace petrochemical plastics in many applications, especially packaging and household appliances. However, these bioplastics are currently more expensive than those of petrochemical origin. It is possible to find several studies in the literature that investigate the use of residues and cheaper substrates, in order to allow large scale production of the PHA. Vegetable oils are widely used in food preparation, most often in the frying process, which leads to large amounts of waste, often incorrectly discarded, causing damage to the environment and the population. Under this consideration, waste frying oils are abundant and can be used in the production of PHA without any further treatment. Therefore, this work studied the production of polyhydroxyalkanoates (PHA) from two strains of bacteria, Pseudomonas oleovorans and Bacillus megaterium, using waste frying oils as a source of carbon (waste oils from potato, chicken and pastel) and were used at concentrations of 10 g.l-1 and 20 g.l-1, separately. The biopolymer production assays were performed in shaken flasks, in nitrogen-limiting culture medium. The dry cell mass (DCM) was determined by gravimetry and the percentage of accumulation and the PHA composition were determined by gas chromatography. The best reaction condition was observed in the residual frying oil from potato, in which the bacterium Bacillus megaterium reached a PHA accumulation of 13.03 % and 3,93 g.l-1 of dry cell mass. From the results obtained it can be concluded that this alternative is promising, besides not competing with the production based on sources of sugar, that is commercially used.
Polyhydroxyalkanoates (PHAs) are a family of biodegradable biopolymers that can replace petrochemical plastics in many applications, especially packaging and household appliances. However, these bioplastics are currently more expensive than those of petrochemical origin. It is possible to find several studies in the literature that investigate the use of residues and cheaper substrates, in order to allow large scale production of the PHA. Vegetable oils are widely used in food preparation, most often in the frying process, which leads to large amounts of waste, often incorrectly discarded, causing damage to the environment and the population. Under this consideration, waste frying oils are abundant and can be used in the production of PHA without any further treatment. Therefore, this work studied the production of polyhydroxyalkanoates (PHA) from two strains of bacteria, Pseudomonas oleovorans and Bacillus megaterium, using waste frying oils as a source of carbon (waste oils from potato, chicken and pastel) and were used at concentrations of 10 g.l-1 and 20 g.l-1, separately. The biopolymer production assays were performed in shaken flasks, in nitrogen-limiting culture medium. The dry cell mass (DCM) was determined by gravimetry and the percentage of accumulation and the PHA composition were determined by gas chromatography. The best reaction condition was observed in the residual frying oil from potato, in which the bacterium Bacillus megaterium reached a PHA accumulation of 13.03 % and 3,93 g.l-1 of dry cell mass. From the results obtained it can be concluded that this alternative is promising, besides not competing with the production based on sources of sugar, that is commercially used.
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Palavras-chave
Óleo residual de fritura, Resíduos, Polihidroxialcanoatos, Bioplásticos, Waste frying oil, Residues, Polyhydroxyalkanoates, Bioplastics