NOVELTY - A recombinant yeast cell for production of ethanol from an oligosaccharide, comprising a heterologous polynucleotide encoding a yeast alpha-glucoside transporter-1 (AGT1) polypeptide, where the yeast AGT1 polypeptide comprises an amino acid sequence that is at least 98% identical to the amino acid sequence containing 616 amino acids or its N-terminal fragment of at least about 590 amino acids, is new.    USE - As recombinant yeast cell for production of ethanol from an oligosaccharide (claimed), where ethanol is used as fuel.    ADVANTAGE - The amount of ethanol produced during fermentation reaches half maximum within 15 (preferably within 10) hours of contacting the oligosaccharide. The method efficiently uses variants of the sugar transporter AGT1 (alpha-glucoside transporter-1) that provide enhanced fermentation of oligosaccharides when recombinantly expressed in yeast. The method exhibits increased efficiency in the ethanol producing process; and addresses drawbacks of prior art by providing an improved fermentation process that enhances the level and rate of fermentation of oligosaccharides.    DETAILED DESCRIPTION - A recombinant yeast cell for production of ethanol from an oligosaccharide, comprising a heterologous polynucleotide encoding a yeast alpha-glucoside transporter-1 (AGT1) polypeptide, where the yeast AGT1 polypeptide comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID No. 1 containing 616 amino acids or its N-terminal fragment of at least about 590 amino acids, is new. INDEPENDENT CLAIMS are included for the following:    (1) fermenting an oligosaccharide to produce ethanol, involving contacting the oligosaccharide with a recombinant yeast cell comprising a heterologous polynucleotide encoding a yeast alpha-glucoside transporter-1 (AGT1) polypeptide, where the yeast AGT1 polypeptide comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID No. 1 or its N-terminal fragment of at least about 590 amino acids;    (2) a method of modifying a yeast cell to decrease lag time for ethanol production during fermentation of an oligosaccharide, involving inserting into the yeast cell, a polynucleotide encoding a yeast AGT1 polypeptide, where the yeast AGT1 polypeptide comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID No. 1 or its N-terminal fragment of at least about 590 amino acids; and    (3) a method of modifying a yeast cell to increase the amount of ethanol production during fermentation of an oligosaccharide, involving inserting into the yeast cell, a polynucleotide encoding a yeast AGT1 polypeptide, where the yeast AGT1 polypeptide comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID No. 1 or its N-terminal fragment of at least about 590 amino acids.