Processo biotecnolÃgico para conversÃo de algaroba (Prosopis juliflora (SW) D.C.) em etanol

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

In order to reduce the impact caused by gases in the greenhouse effect it is becoming necessary the utilization of biomass derivatives as alternative biofuels originated from renewable substrates. Mesquite [Prosopis juliflora (Sw.) D.C.] is a tropical arboreous leguminous plant fairly common in the semi-arid region of Brazil that thrives well in dry environments. The main aim of the present work was to produce ethanol from an aqueous extract obtained from mesquite flour fermented by Saccharomyces cerevisiae and Zymomonas mobilis. The following steps were performed in order to validate this work: chemical and microbiological characterization of the mesquite flour; quantification of flour concentration necessary to obtain the substrate; microorganisms growth curves; fermentations following factorial planning at 23. The fermentative process was conducted up to 72h using the factorial planning which obtained the higher ethanol production (g/L), and analyzed using the linear regression analysis and by calculating the fermentation parameters. It was verified that mesquite flour presented high levels of nutrients, especially sugars and minerals, such as phosphorous and calcium, and was considered appropriated regarding its sanitary conditions. The concentration of 30% was chosen for substrate production due to its stability regarding glucose and total protein solubilization in the medium. Zymomonas mobilis demonstrated better growth in standard medium without agitation, and Saccharomyces cerevisiae showed better growth in substrate under agitation. Based on the factorial planning results, the higher ethanol production was obtained using the aqueous extract from mesquite fermented by Z. mobilis without agitation. Linear regression analysis promoted a good data adjustment regarding the bacterial growth of 0 at 36 hours and ethanol production of 2 at 36 hours. The higher ethanol production, higher substrate conversion into ethanol, and therefore, higher fermentation efficiency was observed at 30h. In conclusion, mesquite represents a viable raw product for biotechnological processes, prompting its usage and conferring aggregated value to the product

ASSUNTO(S)

algaroba saccharomyces cerevisiae ethanol fermentaÃÃo etanol biotechnology zymomonas mobilis nutricao biotecnologia fermentation zymomonas mobilis saccharomyces cerevisiae mesquite

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