Recuperação e purificação de ramnolipídeos produzidos por pseudomonas aeruginosa P029-GVIIA utilizando melaço de cana como substrato

Biosurfactants are molecules produced by microorganisms mainly bacteria as Pseudomonas and Bacillus. Among the biosurfactants, rhamnolipids play an important role due to their tensoactive as well as emulsifying properties. Besides can be produced in a well consolidated way the production costs of biosurfactants are quite expansive mainly if downstream processing is goning to be considered. Actually, attention has been given to identification of biosurfactants as well as optimization of its fermentative processes including downstream ones. This work deals with the development of strategies to recovery and purification of rhamnolipids produced by Pseudomonas aeruginosa P029-GVIIA using sugar-cane molasses as substrate. Broth free of cells was used in order to investigate the best strategies to recovery and purification produced by this system. Between the studied acids (HCl and H2SO4) for the acid precipitation step, HCl was the best one as has been showed by the experimental design 24. Extraction has been carried out using petroleum ether and quantification has been done using the thioglycolic acid method. Adsorption studies were carried out with activated carbon in a batch mode using a 24 experimental design as well as combined with an hydrophobic resin Streamline Phenyl aiming to separate the produced biosurfactant. Biosurfactant partial identification was carried out using High Performance Liquid Chromatography (HPLC). Experiments in batch mode showed that adsorption has been controlled mainly by pH and temperature. It was observed a reduction of 41.4% for the liquid phase and the solid phase it was possible to adsorb up to 15 mg of rhamnolipd/g of activated carbon. The kinetics of adsorption has been well fitted to a pseudo-first order reaction with velocity constant (k1) of 1.93 x 10-2 min-1. Experiments in packed bed ranging concentration on eluent (acetone) has been shown the highest recovery factor of 98% when pure acetone has been used. The combined effect if using activated carbon with an hydrophobic resin Streamline Phenyl has been shown successful for the rhamnolipids purification. It has been possible to purify a fraction of the crude broth with 98% of purity when the eluted of activated carbon packed bed was used with pure acetone

Avaliação do potencial da fibra e casca de coco maduro, casca de coco verde e cacto pré-tratados visando à produção de etanol

The present work investigated the potential of different residual lignocellulosic materials generated in rural and urban areas (coconut fibre mature, green coconut shell and mature coconut shell), and vegetable cultivated in inhospitable environments (cactus) aimed at the production of ethanol, being all materials abundant in the Northeast region of Brazil. These materials were submitted to pretreatments with alkaline hydrogen peroxide followed by sodium hydroxide (AHP-SHP), autohydrolysis (AP), hydrothermal catalyzed with sodium hydroxide (HCSHP) and alkali ethanol organosolv (AEOP). These materials pretreated were submitted to enzymatic hydrolysis and strategies of simultaneous saccharification and fermentation (SSF) and saccharification and fermentation semi-simultaneous (SSSF) by Saccharomyces cerevisiae, Zymomonas mobilis and Pichia stipitis. It was also evaluated the presence of inhibitory compounds (hydroxymethylfurfural, furfural, acetic acid, formic acid and levulinic acid) and seawater during the fermentative process. Materials pretreated with AHP-SHP have resulted in delignification of the materials in a range between 54 and 71%, containing between 51.80 and 54.91% of cellulose, between 17.65 and 28.36% of hemicellulose, between 7.99 and 10.12% of lignin. Enzymatic hydrolysis resulted in the conversions in glucose between 68 and 76%. Conversion yields in ethanol using SSF and SSSF for coconut fibre mature pretreated ranged from 0.40 and 0.43 g/g, 0.43 and 0.45 g/g, respectively. Materials pretreated by AP showed yields of solids between 42.92 and 92.74%, containing between 30.65 and 51.61% of cellulose, 21.34 and 41.28% of lignin. Enzymatic hydrolysis resulted in glucose conversions between 84.10 and 92.52%. Proceeds from conversion into ethanol using green coconut shell pretreated, in strategy SSF and SSSF, were between 0.43 and 0.45 g/g. Coconut fibre mature pretreated by HCSHP presented solids yields between 21.64 and 60.52%, with increased in cellulose between 28.40 and 131.20%, reduction of hemicellulose between 43.22 and 69.04% and reduction in lignin between 8.27 and 89.13%. Enzymatic hydrolysis resulted in the conversion in glucose of 90.72%. Ethanol yields using the SSF and SSSF were 0.43 and 0.46 g/g, respectively. Materials pretreated by AEOP showed solid reductions between 10.75 and 43.18%, cellulose increase up to 121.67%, hemicellulose reduction up to 77.09% and lignin reduced up to 78.22%. Enzymatic hydrolysis resulted in the conversion of glucose between 77.54 and 84.27%. Yields conversion into ethanol using the SSF and SSSF with cactus pretreated ranged from 0.41 and 0.44 g/g, 0.43 and 0.46 g/g, respectively. Fermentations carried out in bioreactors resulted in yields and ethanol production form 0.42 and 0.46 g/g and 7.62 and 12.42 g/L, respectively. The inhibitory compounds showed negative synergistic effects in fermentations performed by P. stipitis, Z. mobilis and S. cerevisiae. Formic acid and acetic acid showed most significant effects among the inhibitory compounds, followed by hydroxymethylfurfural, furfural and levulinic acid. Fermentations carried out in culture medium diluted with seawater showed promising results, especially for S. cerevisiae (0.50 g/g) and Z. mobilis (0.49 g/g). The different results obtained in this study indicate that lignocellulosic materials, pretreatments, fermentative processes strategies and the microorganisms studied deserve attention because they are promising and capable of being used in the context of biorefinery, aiming the ethanol production.