Fermentive production of four carbon alcohols

摘要

Methods for the fermentative production of four carbon alcohols is provided. Specifically, butanol, preferably isobutanol is produced by the fermentative growth of a recombinant bacterium expressing an isobutanol biosynthetic pathway.

主权项

1. A method of converting a renewable feedstock to a feedstock chemical comprising:
a) providing a recombinant yeast host cell that expresses an engineered biosynthetic isobutanol pathway, wherein the engineered biosynthetic isobutanol pathway comprises an acetolactate synthase (ALS) enzyme, a ketol-acid reductoisomerase (KARI) enzyme, a dihydroxy-acid dehydratase (DHAD) enzyme, a branched chain keto acid decarboxylase enzyme (DC), and an alcohol dehydrogenase (ADH) enzyme, each of which is encoded by a heterologous gene that lacks a mitochondrial targeting sequence; and b) growing the yeast host cells in fermentation medium comprising a renewable feedstock, whereby isobutanol is bioproduced from the renewable feedstock and is capable of being used as a chemical feedstock; wherein the yeast host cells produce 2- to 6-fold more isobutanol when grown on sucrose under aerobic conditions compared to a recombinant yeast host cell lacking the engineered biosynthetic isobutanol pathway.