Archer Daniels Midland Company

Sean Jordan

John N D'Elia

Beth Fatland-Bloom

Lhing-Yew Li

Disclosed herein is a newly discovered problem and solution for engineeringto ferment xylose to make ethanol utilizing xylose isomerase to convert xylose to xylulose for entry, via xylulokinase, into the pentose phosphate pathway. The problem is that when grown on a media containing xylose xylitol tends to accumulate in the cell despite the absence of xylose reductase activity in. Xylitol inhibits the activity of xylose isomerases. One solution described is to simultaneously express an exogenous xylitol dehydrogenase along with the exogenous xylose isomerase while optionally also overexpressing xylulokinase in the absence of expression of a xylose reductase. Another solution is a xylose isomerase fromwhich is less inhibited by xylitol than other xylose isomerases, exemplified byxylose isomerase. Expression of thexylose isomerase may be used alone, or in combination with expression of a xylitol dehydrogenase and optionally over expression of xylulokinase to improve ethanol production from xylose.

[object Object]

The invention provides microbial strains possessing improved properties for production of aspartate-derived amino acids and chemicals. Methods of making such strains are provided. These methods include altering expression of the aceBAK operon, the glcB gene, or both. Alteration of expression may be accomplished through increased transcription, relief from native transcriptional control, and/or other means. Replacement of native promoters for these genes is also contemplated; for instance, their native promoters may be replaced by the tac promoter (Ptac).

Altered glyoxylate shunt for improved production of aspartate-derived amino acids and chemicals

The invention relates to novel bacterial strains and constructs as well as methods for production of L-amino acids, including but not limited to L-threonine. Such novel bacterial strains may be characterized by, for instance,strains in which an aspartate semialdehyde dehydrogenase (asd) gene is operably associated with at least one non-native promoter, non-native ribosome binding site, or both.

Growing community of inventors

Decatur, IL, United States of America

Sean Jordan