Potencial de microalgas regionais cultivadas em meios alternativos para produção de biodiesel

• Autor(a) principal: Calixto, Clediana Dantas
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/9210
• topic: Microalgas; Meios residuais; Biocombustíveis; Composição bioquímica; Perfil de FAME; Microalgae; Alternative media; Biofuels; Biochemical composition; FAME profile; CIENCIAS EXATAS E DA TERRA::QUIMICA

Microalgae are microorganisms with high levels of lipids, proteins, carbohydrates and various metabolites of interest to biofuel and nutraceutical compounds industry. Despite numerous indications for its use as a source for biodiesel production, there are still scientific and technological obstacles that prevent this large-scale production. So this study aimed to evaluate the potential of microalgae strains, isolated from the Northeast of Brazil, for biodiesel production, taking into account their cell growth rates, fuel properties that each biodiesel present and the development of these species in waste media arising from human and agro-industrial activities. Besides analyzing the metabolic changes during the growth stages of some species through conventional and FTIR techniques. Were identified eight species potentials for biodiesel production: Pediastrum tetras (D121WC), Scenedesmus acuminatus (D115WC), Chlamydomonas sp. (D132WC) Lagerheimia longiseta (D133WC), Amphora sp. (M84C), Monoraphidium contortum (D173WC), Chlorella sp. (D101Z) and Cosmarium sp. (D174WC), whose biomass productivity was high, ranging from 0.28 to 0.95 g L-1 d-1 and the ester contents were up to 2.9 times higher than soybeans. As regards the evaluation of fuel parameters of a possible biodiesel produced by microalgae, statistical analysis discriminated chloroficea D101Z as promising species for all the high lipid productivity, low clogging point value filter cold and sharp little iodine value. However, it was found that among the twelve species studied, only chloroficea Monoraphidium contortum and cyanobacterium Synechococcus nidulans not meet the fuel quality specifications. In studies of alternative culture medium, it was observed that formulations with domestic sewage (MDS) and biocomposts of fruit/horticultural wastes (HB) demonstrated promising results for cultivation, especially of Chlorella sp., Chlamydomonas sp., and Lagerheimia longiseta, which demonstrated productivities superior to those seen when grown on the control media. The highest concentrations of lipids were obtained in medium BH and changes in the biochemical composition and esters profile species were observed by varying the culture medium. It was also verified that the protein, carbohydrate and lipid accumulation occurs so distinct phases and the microalgal growth, particularly when modifying the culture medium. And from this perspective that the FTIR technique has demonstrated effectiveness in monitoring these components, especially lipids, which showed for all samples a direct relationship with the conventional technique. A general way species viable for large scale production, can grow in waste media have been proposed in this study.