8 research outputs found
A comparison between histopathology and findings on magnetic resonance imaging of subcutaneous lipomatous soft-tissue tumors
Beperkt rugtrauma bij een pati\uebnt met een rigide wervelkolom: een diagnostische valkuil
Traumatisme dorsal limit\ue9 chez un patient avec colonne vert\ue9brale rigide: un \ue9cueil diagnostique
Beperkt rugtrauma bij een pati\uebnt met een rigide wervelkolom: een diagnostische valkuil
Engineering of Saccharomyces cerevisiae for Efficient Anaerobic Alcoholic Fermentation of l-Arabinoseâ–¿
For cost-effective and efficient ethanol production from lignocellulosic fractions of plant biomass, the conversion of not only major constituents, such as glucose and xylose, but also less predominant sugars, such as l-arabinose, is required. Wild-type strains of Saccharomyces cerevisiae, the organism used in industrial ethanol production, cannot ferment xylose and arabinose. Although metabolic and evolutionary engineering has enabled the efficient alcoholic fermentation of xylose under anaerobic conditions, the conversion of l-arabinose into ethanol by engineered S. cerevisiae strains has previously been demonstrated only under oxygen-limited conditions. This study reports the first case of fast and efficient anaerobic alcoholic fermentation of l-arabinose by an engineered S. cerevisiae strain. This fermentation was achieved by combining the expression of the structural genes for the l-arabinose utilization pathway of Lactobacillus plantarum, the overexpression of the S. cerevisiae genes encoding the enzymes of the nonoxidative pentose phosphate pathway, and extensive evolutionary engineering. The resulting S. cerevisiae strain exhibited high rates of arabinose consumption (0.70 g h−1 g [dry weight]−1) and ethanol production (0.29 g h−1 g [dry weight]−1) and a high ethanol yield (0.43 g g−1) during anaerobic growth on l-arabinose as the sole carbon source. In addition, efficient ethanol production from sugar mixtures containing glucose and arabinose, which is crucial for application in industrial ethanol production, was achieved