Gene duplications for crabtree-warburg-like aerobic xylose fermentation

A recombinant yeast that has been genetically engineered to:

• (a) include one or more copies of one or more non-native genes that facilitate xylose fermentation, wherein the non-native genes encode a xylulokinase or a xylose isomerase;
• (b) include one or more additional copies of one or more genes that encode a transaldolase or a transketolase, or both;
• and
• (c) include a disabling mutation in a gene encoding Cox15 polypeptide so as to exhibit reduced amounts of functional Cox15 polypeptide;
• and optionally include one or more of a disabling mutation in a gene encoding Isu1 polypeptide so as to exhibit reduced amounts of functional Isu1 polypeptide, a disabling mutation in a gene encoding Hog1 polypeptide so as to exhibit reduced amounts of functional Hog1 polypeptide, a disabling mutation in a gene encoding Ira2 polypeptide so as to exhibit reduced amounts of functional Ira2 polypeptide, or a disabling mutation in a gene encoding Gre3 polypeptide so as to exhibit reduced amounts of functional Gre3 polypeptide, or any combination thereof;
• or
• a recombinant yeast that has been genetically engineered to:
• (a) include two or more copies of two or more non-native genes that include genes that encode a xylulokinase and a xylose isomerase, and one or more additional copies of a native gene that encodes a transaldolase;
• or
• (b) include one or more additional copies of one or more native genes that include a gene that encodes a transketolase;
• and optionally include one or more of a disabling mutation in a gene encoding Cox15 so as to exhibit reduced amounts of functional Cox15 polypeptide, a disabling mutation in a gene encoding Isu1 polypeptide so as to exhibit reduced amounts of functional Isu1 polypeptide, a disabling mutation in a gene encoding Hog1 polypeptide so as to exhibit reduced amounts of functional Hog1 polypeptide, a disabling mutation in a gene encoding Ira2 polypeptide so as to exhibit reduced amounts of functional Ira2 polypeptide, or a disabling mutation in a gene encoding Gre3 polypeptide so as to exhibit reduced amounts of functional Gre3 polypeptide, or any combination thereof.