Abstract
alpha-Amylase genes of Bacillus licheniformis and glucoamylase cDNA of Aspergillus niger were ligated to a E. coli-yeast shuttle vector. The resultant plasmid was used to transform Saccharomyces cerevisiae to construct starch-degrading yeast strain. The results of enzyme activity assay and enzyme property analysis show that alpha-amylase and glucoamylase genes have been expressed simultaneously in yeast under the control of promoters and terminators of yeast MF-alpha 1 factor and PGK genes and over 99% of enzyme activities were secreted to the medium. The engineered yeast strain hydrolyses 97% of the starch (10%) in the medium after 6 days. The recombinant plasmid exists stably in yeast.
MeSH terms
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Aspergillus niger / enzymology
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Aspergillus niger / genetics
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Bacillus / enzymology
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Bacillus / genetics
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Bacterial Proteins / biosynthesis
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Bacterial Proteins / genetics
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Cloning, Molecular
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Fungal Proteins / biosynthesis
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Fungal Proteins / genetics
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Glucan 1,4-alpha-Glucosidase / biosynthesis*
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Glucan 1,4-alpha-Glucosidase / genetics
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Mating Factor
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Peptides / genetics
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Phosphoglycerate Kinase / genetics
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Recombinant Fusion Proteins / biosynthesis*
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Recombinant Fusion Proteins / genetics
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism*
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Starch / metabolism
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alpha-Amylases / biosynthesis*
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alpha-Amylases / genetics
Substances
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Bacterial Proteins
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Fungal Proteins
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Peptides
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Recombinant Fusion Proteins
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Mating Factor
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Starch
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Phosphoglycerate Kinase
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alpha-Amylases
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Glucan 1,4-alpha-Glucosidase