The present disclosure relates to a composition for producing tagatose comprising a protein having fructose-4-epimerase activity and a method for producing tagatose using the same.

The current disclosure provides a process for enzymatically converting a saccharide into tagatose. The invention also relates to a process for preparing tagatose where the process involves converting fructose 6-phosphate (F6P) to tagatose 6-phosphate (T6P), catalyzed by an epimerase, and converting the T6P to tagatose, catalyzed by a phosphatase.

Provided are a composition for producing tagatose, comprising fructose-4-epimerase, and a method of producing tagatose using the same.

The present invention provides a genetically modified lactic acid bacterium capable of producing diacetyl under aerobic conditions. Additionally the invention provides a method for producing diacetyl using the genetically modified lactic acid bacterium under aerobic conditions in the presence of a source of iron-containing porphyrin and a metal ion selected from Fe.sup.3+, Fe.sup.2+ and Cu.sup.2+. The lactic acid bacterium is genetically modified by deletion of those genes in its genome that encode polypeptides having lactate dehydrogenase (E.C 1.1.1.27/E.C.1.1.1.28); -acetolactate decarboxylase (E.C 4.1.1.5); water-forming NADH oxidase (E.C. 1.6.3.4); phosphotransacetylase (E.C.2.3.1.8) activity; and optionally devoid of or deleted for genes encoding polypeptides having diacetyl reductase ((R)-acetoin forming; EC:1.1.1.303); D-acetoin reductase; butanediol dehydrogenase ((R,R)-butane-2,3-diol forming; E.C. 1.1.1.4/1.1.1.-) and alcohol dehydrogenase (E.C. 1.2.1.10) activity. The invention provides for use of the genetically modified lactic acid bacterium for the production of diacetyl and a food product.

Provided are a composition for producing tagatose, comprising fructose-4-epimerase, and a method of producing tagatose using the same.

The current disclosure provides a process for enzymatically converting a saccharide into tagatose. The invention also relates to a process for preparing tagatose where the process involves converting fructose 6-phosphate (F6P) to tagatose 6-phosphate (T6P), catalyzed by an epimerase, and converting the T6P to tagatose, catalyzed by a phosphatase.

The present disclosure relates to tagatose-6-phosphate phosphatase consisting of an amino acid sequence of SEQ ID NO: 1, a nucleic acid encoding the tagatose-6-phosphate phosphatase, and a transformant comprising the nucleic acid. Additionally, the present disclosure relates to a composition for producing tagatose, which comprises the tagatose-6-phosphate phosphatase of the present disclosure, and a method for producing tagatose using the tagatose-6-phosphate phosphatase of the present disclosure.

Provided are a biomimetic silicon mineralized microcapsule immobilized multi-enzyme, a preparation method therefor, and a method for producing tagatose by using same. The preparation method comprises the following steps: (1) pre-mixing glucan phosphorylase, phosphoglucomutase, phosphoglucoisomerase, 6-phosphate tagatose 4-position epimerase and 6-phosphate tagatose phosphatase solutions, then adding the mixture to a calcium chloride solution, and then pouring same into a sodium carbonate solution, stirring and separating same to obtain calcium carbonate microspheres containing a multi-enzyme; (2) mixing the calcium carbonate microspheres with a polyethyleneimine solution to obtain polyethyleneimine-calcium carbonate microspheres after separation; (3) mixing the polyethyleneimine-calcium carbonate microspheres with a silicate solution to obtain biomimetic silicon mineralized-calcium carbonate microspheres after separation; and (4) mixing the biomimetic silicon mineralized-calcium carbonate microspheres with ethylenediamine tetraacetic acid for reaction to remove calcium carbonate, and separating same to obtain a biomimetic silicon mineralized microcapsule immobilized multi-enzyme.

Provided are the immobilization of multiple enzymes on the basis of an artificial oil body and an application thereof in the preparation of tagatose. Specifically, an artificial oil body is used to mix an expressed fusion protein of target protease-oil body protein with an oil body, which then undergoes an ultrasonic treatment; the fusion protein is anchored to the surface of the oil body by means of the specific hydrophobicity of a human protein to form an artificial oil body containing the target protease, so that the purification and immobilization of enzymes can be completed simultaneously. The immobilized multiple enzymes that can be used for tagatose production utilize an artificial oil body as an immobilized enzyme substrate, which significantly improves the stability of the immobilized enzymes, reduces the production cost of the current enzymatic preparation of tagatose, and has a simple preparation process.

The current disclosure provides a process for enzymatically converting a saccharide into tagatose. The invention also relates to a process for preparing tagatose where the process involves converting fructose 6-phosphate (F6P) to tagatose 6-phosphate (T6P), catalyzed by an epimerase, and converting the T6P to tagatose, catalyzed by a phosphatase.