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.

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 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.

It is an object of an aspect of the present invention to provide (i) transformants, whose proliferation depends on phosphite, of various species of organism and (ii) a method for detecting the presence of a reduced phosphorous compound with use of such a transformant. Use is made of a transformant which is defective in functions of a gene encoding a phosphate transporter protein and a gene encoding a phosphate ester transporter protein and into which a gene encoding a hypophosphite transporter protein is introduced, a signal peptide of a hypophosphite binding protein being substituted with a signal peptide derived from a host or a species of organism closely related to the host.

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.

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.

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, and pharmaceuticals.

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, and pharmaceuticals.

The present invention relates to the technical field of biosynthesis, and in particular to a method for preparing S-nicotine. Amine oxidase is utilized to oxidize 1-methylpyrrolidine into corresponding imine, and then the imine and nicotinic acid are condensed and decarboxylated under the catalysis of nicotine synthetase to obtain a final product S-nicotine. The S-nicotine having specific chirality can be obtained by means of two-step reaction in a reaction system, the synthetic route is short, the yield is high, the reaction conditions are mild, and large-scale production is easy to achieve; moreover, raw materials are wide in source, low in price, low in production cost and environmentally friendly, the production cost of nicotine is remarkably reduced, and the requirements of current green industrial production can be better satisfied.

The invention provides genetically modified cyanobacterial cells that are capable of utilizing phosphite as a primary phosphorus source, and can out-compete contaminant organisms for certain forms of phosphorus more effectively.