Encontrados 7 documentos, a visualizar página 1 de 1

Fermentation medium and oxygen transfer conditions that maximize the xylose con...

The xylose conversion to ethanol by Pichia stipitis was studied. In a first step, the necessity of supplementing the fermentation medium with urea, MgSO4 × 7H2O, and/or yeast extract was evaluated through a 23 full factorial design. The simultaneous addition of these three nutritional sources to the fermentation medium, in concentrations of 2.3, 1.0, and 3.0 g/l, respectively, showed to be important to improve ...

Technological trends, global market, and challenges of bio-ethanol production

Ethanol use as a fuel additive or directly as a fuel source has grown in popularity due to governmental regulations and in some cases economic incentives based on environmental concerns as well as a desire to reduce oil dependency. As a consequence, several countries are interested in developing their internal market for use of this biofuel. Currently, almost all bio-ethanol is produced from grain or sugarcane....

A study on chemical constituents and sugars extraction from spent coffee grounds

Spent coffee grounds (SCG), the residual materials obtained during the processing of raw coffee powder to prepare instant coffee, are the main coffee industry residues. In the present work, this material was chemically characterized and subsequently submitted to a dilute acid hydrolysis aiming to recover the hemicellulose sugars. Reactions were performed according to experimental designs to verify the effects o...

The influence of initial xylose concentration, agitation, and aeration on ethan...

Rice straw hemicellulosic hydrolysate was used as fermentation medium for ethanol production by Pichia stipitis NRRL Y-7124. Shaking bath experiments were initially performed aiming to establish the best initial xylose concentration to be used in this bioconversion process. In the sequence, assays were carried out under different agitation (100 to 200 rpm) and aeration (V flask/V medium ratio varying from 2.5 t...

Avaliação do processo de bioprodução de etanol a partir de xilose pela levedura...

A produção de etanol pela levedura Pichia stipitis foi avaliada em reator de bancada sob diferentes condições de aeração e agitação em meio semi-sintético contendo xilose (90,0 g/L) como principal fonte de carbono. Os ensaios foram realizados segundo um planejamento fatorial 2² variando-se a aeração (0,25 a 0,75 vvm) e a agitação (150 a 250 rpm). Dentro da região de transferência de oxigênio estudada, o fator d...

Kinetic behavior of ethanol production by Pichia stipitis under high xylose con...

A perspectiva do comandante Edward Boid, oficial inglês e romântico.

O ano de 1832 trouxe aos Açores a célebre expedição liberal liderada por D. Pedro e constituída quase inteiramente por militares britânicos. Integrado neste contingente militar estava o comandante Edward Boid, autor de "A Description of the Azores or Western Islands" (1834), relato de viagem onde registou as experiências colhidas no Arquipélago. A narrativa encerra duas visões opostas mas complementares das Ilh...