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https://hdl.handle.net/1822/23377
Título: | The effect of the electric field on lag phase, β-galactosidase production and plasmid stability of a recombinant Saccharomyces cerevisiae strain growing on lactose |
Autor(es): | Castro, Inês Oliveira, Carla Cristina Marques de Domingues, Lucília Teixeira, J. A. Vicente, A. A. |
Palavras-chave: | β-galactosidase Electric field Growth Plasmid stability . Recombinant S. cerevisiae strain beta-galactosidase Growth parameters Plasmid stability Recombinant S. cerevisiae strain |
Data: | 2012 |
Editora: | Springer |
Revista: | Food and Bioprocess Technology |
Resumo(s): | Ethanol and β-galactosidase production from cheese whey may significantly contribute to minimise environmental problems while producing value from lowcost raw materials. In this work, the recombinant Saccharomyces cerevisiae NCYC869-A3/pVK1.1 flocculent strain expressing the lacA gene (coding for β-galactosidase) of Aspergillus niger under ADHI promoter and terminator was used. This strain shows high ethanol and β-galactosidase productivities when grown on lactose. Batch cultures were performed using SSlactose medium with 50 gL−1 lactose in a 2-L bioreactor under aerobic and microaerophilic conditions. Temperature was maintained at 30 °C and pH 4.0. In order to determine the effect of an electric field in the fermentation profile, titanium electrodes were placed inside the bioreactor and different electric field values (from 0.5 to 2 Vcm−1) were applied. For all experiments, β-galactosidase activity, biomass, protein, lactose, glucose, galactose and ethanol concentrations were measured. Finally, lag phase duration and specific growth rate were calculated. Significant changes in lag phase duration and biomass yield were found when using 2 Vcm−1. Results show that the electric field enhances the early stages of fermentation kinetics, thus indicating that its application may improve industrial fermentations’ productivity. The increase in electric field intensity led to plasmid instability thus decreasing β-galactosidase production. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/23377 |
DOI: | 10.1007/s11947-011-0609-4 |
ISSN: | 1935-5130 |
e-ISSN: | 1935-5149 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series |
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