Provided herein are methods, compositions, and non-naturally occurring microbial organism for preparing compounds such as α-butanol, butyric acid, succinic acid, 1,4-butanediol, 1-pentanol, pentanoic acid, glutaric acid, 1,5-pentanediol, 1-hexanol, hexanoic acid, adipic acid, 1,6-hexanediol, 6-hydroxy hexanoic acid, ε-Caprolactone, 6-amino-hexanoic acid, ε-Caprolactam, hexamethylenediamine, linear fatty acids and linear fatty alcohols that are between 7-25 carbons long, linear alkanes and linear α-alkenes that are between 6-24 carbons long, sebacic acid and dodecanedioic acid comprising: a) converting a C.sub.N aldehyde and pyruvate to a C.sub.N+3 β-hydroxyketone intermediate through an aldol addition; and b) converting the C.sub.N+3 β-hydroxyketone intermediate to the compounds through enzymatic steps, or a combination of enzymatic and chemical steps.

Yeast cells having a reductive TCA pathway from pyruvate or phosphoenolpyruvate to succinate, and which include at least one exogenous gene overexpressing an enzyme in that pathway, further contain an exogenous transhydrogenase gene.

The present application provides genetically modified yeast cell comprising an active succinate fermentation pathway, as well as methods of using these cells to produce succinate.

The present invention relates to recombinant factor H and variants and conjugates thereof and methods of their production, as well as uses and methods of treatment involving the materials.

The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct fumaric acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which a fumarate hydratase gene fum is knocked out. The disclosure overcomes the defects in the prior art, in the current process of producing malic acid through fermentation of Aspergillus niger, byproduct fumaric acid can be accumulated with the generation of malic acid so as to cause the improved cost of the subsequent malic acid purification process. The disclosure provides an Aspergillus niger engineered strain in which a fum gene is knocked out and a method for greatly reducing byproduct fumaric acid in the fermentation production of Aspergillus niger.

Presented herein are biocatalysts and methods for the production of succinic acid from carbon sources. The biocatalysts include microbial cells that have been engineered to overexpress exogenously added genes that encode enzymes active in the reductive branch of the tricarboxylic acid (TCA) cycle.

Yeast cells having a reductive TCA pathway from pyruvate or phosphoenolpyruvate to succinate, and which include at least one exogenous gene overexpressing an enzyme in that pathway, further contain an exogenous transhydrogenase gene.

The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct fumaric acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which a fumarate hydratase gene fum is knocked out. The disclosure overcomes the defects in the prior art, in the current process of producing malic acid through fermentation of Aspergillus niger, byproduct fumaric acid can be accumulated with the generation of malic acid so as to cause the improved cost of the subsequent malic acid purification process. The disclosure provides an Aspergillus niger engineered strain in which a fum gene is knocked out and a method for greatly reducing byproduct fumaric acid in the fermentation production of Aspergillus niger.

The disclosure discloses construction and application of an engineered strain of E. coli for producing malic acid by fixing CO.sub.2, and belongs to the field of fermentation. The engineered strain is obtained by performing genetic engineering transformation on Escherichia coli MG1655; the genetic engineering transformation includes knocking out a fumarate reductase gene, a fumarase gene, a lactate dehydrogenase gene and an alcohol dehydrogenase gene and freely overexpressing a formate dehydrogenase, an acetyl coenzyme A synthetase, an acylated acetaldehyde dehydrogenase, a formaldehyde lyase, a dihydroxyacetone kinase, a malic enzyme and a phosphite oxidoreductase to obtain a strain GH0407. The strain is used for producing malic acid by fermentation, anaerobic fermentation is performed for 72 hours with CO.sub.2 and glucose as a co-substrate, the production of malic acid reaches 39 g/L, the yield is 1.53 mol/mol, and accumulation of malic acid in the original strain is not achieved.

Provided herein are genetically modified Issatchenkia yeast and fermentation methods for producing succinic acid.