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

Provided are a fructose-4-epimerase variant having tagatose conversion activity, and a method of preparing tagatose using the same.

The invention relates to immobilized enzyme compositions for the preparation of a hexose. Hexoses include, for example, tagatose, psicose, fructose, allose, mannose, galactose, altrose, talose, sorbose, gulose, idose, and inositol. The invention also relates to an enzymatic process for preparing a hexose from a saccharide by contacting a starch derivative with an immobilized enzyme composition of the invention.

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 Cu2+. 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.

The present invention relates to a method of providing a gene cluster that determines the rare sugar utilization ability of a strain unable to metabolize a rare sugar. A novel sugar metabolic pathway may be constructed using an expression cassette or a vector containing the same according to the present invention, and a mutant strain transformed with the vector or a mutant strain containing a mutated gene has a novel sugar metabolic pathway constructed therein. In addition, the present invention relates to a method for selecting a variant with increased activity, and a composition for selecting a variant with increased activity may be advantageously used to select a variant with increased activity by detecting the mutation of SEQ ID NO: 11.

The present disclosure relates to a composition for tagatose production and a method for preparing tagatose using the same.