Patent ID: 8557562

Claim:
A recombinant yeast cell comprising: (a) an isobutanol biosynthetic pathway, wherein the recombinant yeast cell comprises heterologous genes encoding an acetolactate synthase, an acetohydroxy acid isomeroreductase, an acetohydroxy acid dehydratase or dihydroxyacid dehydratase, a branched-chain keto acid decarboxylase, and a branched-chain alcohol dehydrogenase that perform the following substrate to product conversions: (i) pyruvate to acetolactate catalyzed by the acetolactate synthase, (ii) acetolactate to 2,3-dihydroxyisovalerate catalyzed by the acetohydroxy acid isomeroreductase, (iii) 2,3-dihydroxyisovalerate to α-ketoisovalerate catalyzed by the acetohydroxy acid dehydratase or dihydroxyacid dehydratase, (iv) α-ketoisovalerate to isobutyraldehyde catalyzed by the branched-chain keto acid decarboxylase, and (v) isobutyraldehyde to isobutanol catalyzed by the branched-chain alcohol dehydrogenase; and (b) at least one genetic modification which increases activity of the nitrogen starvation-induced filamentous growth response, wherein the genetic modification is heterologous expression of a transcription factor involved in regulation of invasive growth in response to nutritional signals, wherein the transcription factor has at least 95% sequence identity to the Saccharomyces cerevisiae MSS11 protein of SEQ ID NO: 50, SEQ ID NO: 52, or SEQ ID NO: 54; wherein the yeast cell has an increase in tolerance to isobutanol as compared with the corresponding yeast cell that lacks the at least one genetic modification of (b).