Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

Synthetic polynucleotides encoding human methylmalonyl-CoA mutase (synMUT) and exhibiting augmented expression in cell culture and/or in a subject are described herein. An adeno-associated viral (AAV) gene therapy vector encoding synMUT under the control of a liver-specific promoter (AAV2/8-HCR-hAAT-synMUT-RBG) successfully rescued the neonatal lethal phenotype displayed by methylmalonyl-CoA mutase-deficient mice, lowered circulating methylmalonic acid levels in the treated animals, and resulted in prolonged hepatic expression of the product of synMUT transgene in vivo, human methylmalonyl-CoA mutase (MUT).

Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

Provided herein is a mutant microorganism containing a methylmalonyl-CoA reductase-encoding gene having an activity of converting methylmalonyl-CoA to methylmalonate semialdehyde and uses of the mutant microorganism. The mutant microorganism includes a gene encoding kingdom Archaea-derived methylmalonyl-CoA reductase.

The present invention relates to lentiviral vectors encoding a methylmalonic acidemia (MMA)-associated polypeptide. The present invention also relates to cells and pharmaceutical compositions comprising said lentiviral vectors and to uses of said lentiviral vectors in treating methylmalonic acidemia (MMA).

The present invention provides, among other things, methods and compositions for treating methylmalonic academia (MMA) based on mRNA therapy. The compositions used in treatment of MMA comprise an mRNA comprising a methymalonyl-CoA mutase (MUT) coding sequence and are administered at an effective dose and an administration interval such that at least one symptom or feature of MMA is reduced in intensity, severity, or frequency or has a delayed onset. mRNAs with optimized MUT coding sequences are provided that can be administered without the need for modifying the nucleotides of the mRNA to achieve sustained in vivo function.