Provided are a novel 3-hydroxypropionate-lactate block copolymer [P(3HP-b-LA)], and a method for preparing same, comprising: a) transforming a recombinant microorganism modified to be incapable of biosynthesizing lactic acid with a vector including a 3-hydroxypropionyl-CoA biosynthesis gene and a polyhydroxyalkanoate (PHA) synthetase gene, and a vector including a lactate biosynthesis gene and a gene of an enzyme that converts lactate to lactyl-CoA; (b) synthesizing poly(3-hydroxypropionate) (P(3HP)) by culturing the recombinant microorganism using a glycerol as a carbon source; and (c) inhibiting P(3HP) production by adding IPTG and glucose, and biosynthesizing polylactate (PLA) at the end of P(3HP) synthesized in step (b) by enabling the expression of a lactate biosynthesis enzyme and an enzyme that converts lactate to lactyl-CoA. Also provided is a recombinant microorganism produced in step a).

The invention relates to a genetically engineered thermophilic bacterial cell that is facultative anaerobic comprising: a) inactivation or deletion of the endogenous (S)-lactate dehydrogenase gene; b) introduction of a (R)-lactate dehydrogenase gene; c) inactivation or deletion of the endogenous pyruvate formate lyase A and/or B gene.

Provided herein is D-lactate dehydrogenase, an engineered strain containing the D-lactate dehydrogenase, and a construction method and use of the engineered strain. The D-lactate dehydrogenase has unique properties and is from Thermodesulfatator indicus, and the D-lactate dehydrogenase has good thermophily and heat stability. By using the D-lactate dehydrogenase and the gene engineering reconstruction method, a fermentation product of the reconstructed Bacillus licheniformis can be redirected to optically-pure D-lactic acid with a high yield from naturally produced 2,3-butanediol, and the optical purity of the produced D-lactic acid reaches 99.9%; and raw materials for fermentation are low-cost, and a fermentation state is between an anaerobic fermentation state and a microaerobic fermentation state. By using the method for producing D-lactic acid through fermentation at high temperature, the production cost can be reduced, the production efficiency can be improved and there is a wide industrial application prospect for the method.

The present invention relates to a recombinant microorganism having the ability to produce poly(lactate-co-glycolate) and its copolymers from xylose, and more particularly to a recombinant microorganism having the ability to produce poly(lactate-co-glycolate) and its copolymers without having to supply a glycolate precursor from an external source, and a method of producing a poly(lactate-co-glycolate) copolymers using the same.

A method for the preparation of 2,4-dihydroxybutyric acid from homoserine includes a first step of conversion of the primary amino group of homoserine to a carbonyl group to obtain 2-oxo-4-hydroxybutyrate, and a second step of reduction of the obtained 2-oxo-4-hydroxybutyrate (OHB) to 2,4-dihydroxybutyrate.

The present invention relates to a transformant which uses Schizosaccharomyces pombe as a host into which a D-LDH gene derived from bacteria of the genus Pediococcus and a D-LDH gene derived from bacteria of the genus Lactobacillus are incorporated and in which some of the genes in a group of pyruvate decarboxylase-encoding genes of the Schizosaccharomyces pombe host have been deleted or inactivated.

A method for the preparation of 2,4-dihydroxybutyric acid from homoserine includes a first step of conversion of the primary amino group of homoserine to a carbonyl group to obtain 2-oxo-4-hydroxybutyrate, and a second step of reduction of the obtained 2-oxo-4-hydroxybutyrate (OHB) to 2,4-dihydroxybutyrate.

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.

The present invention relates to a process of producing isobutanol, including: mixing water, lactate, an enzyme mixture including at least one enzyme, at least one cofactor, and at least one coenzyme, to prepare a reaction mixture; allowing catalytic conversions of lactate in the reaction mixture for a sufficient amount of time to produce isobutanol; and separating the isobutanol from a reactant obtained by the catalytic conversions, in which the conversion of lactate into isobutanol is in association with a NADH.sup.+/NADH and/or NADP.sup.+/NADPH regenerating system.

The invention relates to a recombinant cell, preferably a yeast cell comprising one or more genes coding for an enzyme having glycerol dehydrogenase activity, one or more genes coding dihydroxyacetone kinase (E.C. 2.7.1.28 and/or E.C. 2.7.1.29); one or more genes coding for an enzyme in an acetyl-CoA-production pathway and one or more genes coding for an enzyme having at least NAD.sup.+ dependent acetylating acetaldehyde dehydrogenase activity (EC 1.2.1.10 or EC 1.1.1.2), and optionally one or more genes coding for a glycerol transporter. This cell can be used for the production of ethanol and advantageously produces little or no glycerol.