Estudo comparativo de diferentes metodos e condições da fermentação de melaço de cana-de-açucar por Zymomonas mobilis CP4

AUTOR(ES)
DATA DE PUBLICAÇÃO

1993

RESUMO

This study was carried out to characterize the methods and parameters affecting the fermentation of Zymomonas mobilis CP4 on sugar cane molasses as sustrate. Temperature, pH, Ca++, K+, Mg++ and Cl- were the experimental variables using on a saccharose culture medium. Besides, the effects of clarification and nutrients suplementation of sugar cane molasses was studied. Kinetics parameters on sugar cane molasses were analyzed under different experimental conditions: a prototype lab fermenter was used in batch, fed-batch and continuous fermentations, and a pilot prototype scale was used for batch and fed-batch fermentations. At the same time, fermentation assays in a discontinuous process under laboratory scale procedures were carried out using sugar cane medium and HTM as the sustrate of the fermentation. Growth rate and ethanol production by Zymomonas mobilis CP4 in saccharose and molasses culture medium were optimum at 34 °C. Levan output decreased with increasing temperature and pH control during the fermentation. Clarification treatments in molasses decreased the amount of Ca++ and K+ but not better results in fermentation rate were observed, despite the fact that both ions and chlorides ions exert and inhibitory effect in growing and fermentation activities of Zymomonas mobilis CP4. No negative effect was observed concerning Mg ++. Besides, molasses suplementation with nutrients was necessary to increase yields. In batch process better -kinetics results were obtained with molasses concentrations of 108 g/l. The productivity was higher in continuous process compared with batch and fed-batch processes. The fermentation output obtained with batch process were higher under pilot plant operation in contrait with laboratory scale models. Sugar cane molasses and. sugar cane culture medium were better nutritional products for fermentation purposes but most be supplemented to get better results.

ASSUNTO(S)

cana-de-açucar - derivados fermentação melaço

ACESSO AO ARTIGO

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