The invention relates to a recombinant Escherichia coli expressing a fusion protein of formamidase and phosphite dehydrogenase, a construction method and use thereof. The invention includes adopting engineered E. coli DH5α as a host, amplifying a cloned formamidase gene and a cloned phosphite dehydrogenase gene into a fusion gene, ligating the fusion gene to a multiple cloning site of a vector, transforming the obtained recombinant plasmid into the E. coli DH5α, extracting the plasmid and transforming into an expression strain, and performing induction culture to obtain a recombinant E. coli. The recombinant E. coli can express a fusion protein of formamidase and phosphite dehydrogenase.

The invention discloses an alcohol dehydrogenase mutant and use thereof. The alcohol dehydrogenase mutant of the present invention has high thermal stability and enables high catalytic efficiency and high conversion rate (i.e. space time yield) in the asymmetric reduction of prochiral diaryl ketones to produce chiral diaryl alcohols. Therefore, the alcohol dehydrogenase mutant of the present invention has extremely high prospect of application in the production of chiral diaryl alcohols, such as (S)-(4-chlorophenyl)-(pyridin-2-yl)-methanol, (R)-(4-chlorophenyl)-(pyridin-2-yl)-methanol.

Disclosed are genetically engineered organisms, such as yeast and bacteria, that have the ability to metabolize atypical phosphorus or sulfur sources. Fermentation methods using the genetically engineered organisms are also described. The fermentation methods are robust processes for the industrial bioproduction of a variety of compounds, including commodities, fine chemicals, an pharmaceuticals.

Phosphite dehydrogenase (ptxD) expression was established as a selectable marker for nuclear and chloroplast genetic selection in Picochlorum renovo and Picochlorum celeri Phosphite was used as a sole phosphorus source in P. renovo and P. celeri. Growth on phosphite led to comparable growth and composition relative to phosphate.

The present disclosure relates to genetically modified cells containing mitochondria that have been transformed with a polynucleotide encoding a phosphite dehydrogenase enzyme, such that the cells can utilize phosphite as a phosphorus source.

The present invention relates to methods of metabolic engineering cells to increase their ability to compete with contaminating microorganisms without the need for antibiotics. More particularly, the invention provides methods to engineer cyanobacteria to utilize melamine as nitrogen source, phosphite as phosphorous source, optionally also utilizing NADP+ over NAD+, and also provides genetically engineered cells made using such methods.

The present invention relates to transgenic microalgae for the production of cell wall degradative enzymes having a heat-stable cellulolytic activity (HCWDEs) and their relative uses in the biodegradation of cellulose or lignocellulose sources in the industrial field.

The invention discloses an alcohol dehydrogenase mutant and use thereof. The alcohol dehydrogenase mutant of the present invention has high thermal stability and enables high catalytic efficiency and high conversion rate (i.e. space time yield) in the asymmetric reduction of prochiral diaryl ketones to produce chiral diaryl alcohols. Therefore, the alcohol dehydrogenase mutant of the present invention has extremely high prospect of application in the production of chiral diaryl alcohols, such as (S)-(4-chlorophenyl)-(pyridin-2-yl)-methanol, (R)-(4-chlorophenyl)-(pyridin-2-yl)-methanol.

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.

The present invention provides engineered ketoreductase and phosphite dehydrogenase enzymes having improved properties as compared to a naturally occurring wild-type ketoreductase and phosphite dehydrogenase enzymes, as well as polynucleotides encoding the engineered ketoreductase and phosphite dehydrogenase enzymes, host cells capable of expressing the engineered ketoreductase and phosphite dehydrogenase enzymes, and methods of using the engineered ketoreductase and phosphite dehydrogenase enzymes to synthesize a chiral catalyst used in the synthesis of antiviral compounds, such as nucleoside inhibitors. The present invention further provides methods of using the engineered enzymes to deracemize a chiral alcohol in a one-pot, multi-enzyme system.