Use of bacteriocin-producing ethanologens in biofuel production
AssigneeWisconsin Alumni Research Foundation
InventorsJames L. Steele, Jeffrey Broadbent, Ekkarat Phrommao
Life of this patent
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Abstract
An ethanologen for producing biofuel from one or more carbohydrates and reducing lactate and acetate production in a biofuel manufacturing process. The ethanologen is made by introducing into the ethanologen one or more exogenous genes required for production of a bacteriocin. The resulting ethanologen reduces lactate and acetate production by contaminant lactic acid bacteria by expression of the bacteriocin during the biofuel manufacturing process. Certain resulting ethanologens ferment sugars not naturally or not preferentially utilized by Saccharomyces cerevisiae during the manufacturing process.
Claims19
An ethanologen for inhibiting contaminant lactic acid bacteria present in a biofuel manufacturing process, comprising an ethanologen that is a lactic acid bacterium engineered to produce a biofuel and further engineered to produce a bacteriocin which inhibits contaminant lactic acid bacteria present in the biofuel manufacturing process;
- wherein the ethanologen comprises:
- (a) one or more endogenous genes encoding a mannitol dehydrogenase engineered to be inactive;
- (b) one or more exogenous genes encoding a pyruvate decarboxylase and one or more exogenous genes encoding an alcohol dehydrogenase II;
- and (c) one or more exogenous genes required for production of a bacteriocin;
- whereby the resulting engineered lactic acid bacterium produces more biofuel than a wild-type lactic acid bacterium having the same genetic background in a biofuel manufacturing process and reduces lactate and acetate production in said process by secretion of the bacteriocin, which inhibits contaminant lactic acid bacteria.
A method of making an ethanologen, comprising:
- (a) inactivating within a lactic acid bacterium one or more endogenous genes encoding a mannitol dehydrogenase;
- (b) introducing into a lactic acid bacterium one or more exogenous genes encoding a pyruvate decarboxylase and one or more exogenous genes encoding an alcohol dehydrogenase II;
- and
- (c) introducing into said lactic acid bacterium one or more exogenous genes required for production of a bacteriocin;
- whereby the resulting engineered bacterium produces more biofuel than a wild-type lactic acid bacterium having the same genetic background in a biofuel manufacturing process and reduces lactate and acetate production in said process by secretion of the bacteriocin, which inhibits contaminant lactic acid bacteria.
An ethanologen for use in an ethanol manufacturing process, comprising a Lactobacillus casei 12A derivative having:
- a deletion mutation ΔL-ldh1, an exogenous gene encoding a pyruvate decarboxylase, and an exogenous gene encoding an alcohol dehydrogenase II, wherein the exogenous genes are operably linked to a native L. casei promoter, wherein the engineered bacterium produces ethanol at a greater rate than a wild-type Lactobacillus casei 12A bacterium having the same genetic background, and
- wherein the ethanologen is capable of fermenting sugars not naturally or not preferentially utilized by a main fermenting microbe present in the ethanol manufacturing process
- wherein the ethanologen further comprises one or more mannitol dehydrogenases engineered to be inactive
- whereby the resulting engineered lactic acid bacterium produces more biofuel than a wild-type lactic acid bacterium having the same genetic background in a biofuel manufacturing process and reduces lactate and acetate production in said process by secretion of the bacteriocin, which inhibits contaminant lactic acid bacteria.
Dependencies are inferred from the claim text.