Process for the biological production of 1,3-propanediol with high yield
View Patent ↗The present invention provides a microorganism useful for biologically producing 1,3-propanediol from a fermentable carbon source at higher yield than was previously known. The complexity of the cofactor requirements necessitates the use of a whole cell catalyst for an industrial process that utilizes this reaction sequence to produce 1,3-propanediol. The invention provides a microorganism with disruptions in specified genes and alterations in the expression levels of specified genes that is useful in a higher yielding process to produce 1,3-propanediol.
1. A method for the bioproduction of 1,3-propanediol comprising contacting with a suitable carbon substrate under suitable conditions a E. coli strain comprising:
a) a disrupted endogenous phosphoenolpyruvate-glucose phosphotransferase system comprising one or more of:
i) a genetically disrupted endogenous ptsH gene preventing expression of active phosphocarrier protein;
ii) a genetically disrupted endogenous ptsl gene preventing expression of active phosphoenolpyruvate-protein phosphotransferase; and
iii) a genetically disrupted endogenous crr gene preventing expression of active glucose-specific IIA component;
b) a genetically up regulated endogenous galP gene encoding active galactose-proton symporter, said up regulation resulting in an increased galactose-proton symporter activity, wherein the up regulation is produced by:
i) introducing additional copies of said gene into said E. coli strain followed by integration; or
ii) replacing a native regulatory sequence with a strong non-native promoter or altered native promoter;
c) a genetically up regulated endogenous glk gene encoding active glucokinase, said up regulation resulting in an increased glucokinase activity, wherein the up regulation is produced by:
i) introducing additional copies of said gene into said E. coli strain followed by integration; or
ii) replacing a native regulatory sequence with a strong non-native promoter or altered native promoter; and
d) a genetically down regulated endogenous gapA gene encoding active glyceraldehyde 3-phosphate dehydrogenase, said down regulation resulting in a reduced glyceraldehyde 3-phosphate dehydrogenase activity;
whereby said E. coil strain is capable of bioconverting a suitable carbon source to 1,3-propanediol.
2. The method of claim 1 , wherein the E. coli strain comprises a genetically disrupted endogenous arcA gene preventing expression of active aerobic respiration control protein.
3. The method of claim 1 , wherein the E. coil strain further comprises:
(i) glycerol-3-phosphate dehydrogenase;
(ii) glycerol-3-phosphatase;
(iii) glycerol dehydratase or diol dehydratase; and
(iv) dehydratase reactivation factor.
4. The method of claim 2 , wherein the E. coil strain further comprises:
(i) glycerol-3-phosphate dehydrogenase;
(ii) glycerol-3-phosphatase;
(iii) glycerol dehydratase or diol dehydratase; and
(iv) dehydratase reactivation factor.