An object of the present invention is to provide a novel culturing method by which spores can be efficiently produced. The present invention further provides a method for culturing sporulating bacteria, comprising adding a sporulation-inhibiting substance into a medium for culturing sporulating bacteria, wherein the carbon content in the medium is 9.1 g/L or more, and preferably further comprising a step of adding a sporulation-accelerating substance to the medium.

An object of the present invention is to provide a novel culturing method by which spores can be efficiently produced. The present invention further provides a method for culturing sporulating bacteria, comprising adding a sporulation-inhibiting substance into a medium for culturing sporulating bacteria, wherein the carbon content in the medium is 9.1 g/L or more, and preferably further comprising a step of adding a sporulation-accelerating substance to the medium.

Use of a stereoselective transaminase in the asymmetric synthesis of a chiral amine. In particular, provided is use of a polypeptide in the production of a chiral amine or a downstream product using a chiral amine as a precursor. Further provided is a method for producing a chiral amine, comprising culturing a strain expressing the polypeptide so as to obtain a chiral amine. Further provided are a chiral amine production strain and a method for constructing the chiral amine production strain. The stereoselective transaminase has a broad substrate spectrum and thus has a broad application potential in the preparation of a chiral amine.

Provided is use of immobilized transaminase in preparation of sitagliptin and/or (R)-3-amino-1-morpholine-4-(2,4,5-trifluorophenyl)-1-butanone. The immobilized transaminase comprises resin and a transaminase mutant, the amino acid sequence of the transaminase mutant is as shown in SEQ ID NO: 3 or SEQ ID NO: 7. Also provided is an immobilized transaminase, a transaminase mutant, a preparation method therefor and use thereof. The enzyme activity of the transaminase mutant in the catalysis of a ketoamide substrate is high, and the enzyme activity is still high after the transaminase mutant is prepared into the immobilized transaminase. When the transaminase mutant is used for catalyzing the ketoamide substrate to produce sitagliptin or an intermediate thereof, a screened solvent reaction system is combined, the immobilized transaminase is high in conversion rate and good in stereoselectivity and stability, the repeatability rate is improved, and the operation is simpler, thereby reducing the cost of production, and it is beneficial to industrial production.

Provided is use of immobilized transaminase in preparation of sitagliptin and/or (R)-3-amino-1-morpholine-4-(2,4,5-trifluorophenyl)-1-butanone. The immobilized transaminase comprises resin and a transaminase mutant, the amino acid sequence of the transaminase mutant is as shown in SEQ ID NO: 3 or SEQ ID NO: 7. Also provided is an immobilized transaminase, a transaminase mutant, a preparation method therefor and use thereof. The enzyme activity of the transaminase mutant in the catalysis of a ketoamide substrate is high, and the enzyme activity is still high after the transaminase mutant is prepared into the immobilized transaminase. When the transaminase mutant is used for catalyzing the ketoamide substrate to produce sitagliptin or an intermediate thereof, a screened solvent reaction system is combined, the immobilized transaminase is high in conversion rate and good in stereoselectivity and stability, the repeatability rate is improved, and the operation is simpler, thereby reducing the cost of production, and it is beneficial to industrial production.

Provided is a process for synthesizing a functionalized cyclic dithiocarbamate.

Provided is a process for synthesizing a functionalized cyclic dithiocarbamate.

Use of a stereoselective transaminase in the asymmetric synthesis of a chiral amine. In particular, provided is use of a polypeptide in the production of a chiral amine or a downstream product using a chiral amine as a precursor. Further provided is a method for producing a chiral amine, comprising culturing a strain expressing the polypeptide so as to obtain a chiral amine. Further provided are novel prochiral compounds, a chiral amine production strain and a method for constructing the chiral amine production strain. The stereoselective transaminase has a broad substrate spectrum and thus has a broad application potential in the preparation of a chiral amine.

The present disclosure relates to mutant enzymes and bacterial strains constructed to produce paraxanthine and 7-methylxanthine from caffeine and methods for the manufacture and use thereof.

The present disclosure relates to mutant enzymes and bacterial strains constructed to produce paraxanthine and 7-methylxanthine from caffeine and methods for the manufacture and use thereof.