The present invention provides a dehydrogenase mutant L283V/L286V, and a preparation method and use thereof, and relates to the field of biomedicine technologies. An amino acid sequence of the mutant L283V/L286V is as shown in SEQ ID NO: 1; and the mutant is prepared by simultaneously mutating 283.sup.rd and 286.sup.th leucine of a dehydrogenase with an amino acid sequence as shown in SEQ ID NO: 3 into valine. The dehydrogenase mutant L283V/L286V shows high selectivity in catalyzing myosmine reduction reaction in a whole cell system to produce S-nornicotine, and has relatively high dehydrogenase and imine reductase activities, a short enzyme reduction time, and a high transformation rate. The product S-nornicotine obtained through the reaction has extremely high optical purity, which reduces the operation difficulty of subsequent purification.

Provided is a transformant which can produce lactic acid with a high productivity without requiring neutralization with an alkali and is excellent in both of lactic acid production capability and growth ability and its production process, and a method for producing lactic acid by using the transformant.

A transformant containing from 3 to 5 copies of a lactate dehydrogenase gene derived from human and introduced into a Schizosaccharomyces pombe host, wherein a gene that is a part of a group of genes encoding pyruvate decarboxylase of the Schizosaccharomyces pombe host is deleted or inactivated. A transformant characterized by providing a cell concentration of at least 4.0 g (on a dry cell weight basis)/L of a culture broth prepared by inoculating cells, at an initial cell concentration of 0.04 g (on a dry cell weight basis)/L, into a 500 mL Sakaguchi flask containing 100 mL of a liquid culture broth which includes 1% of yeast extract, 2% of peptone and 6% of glucose, and then cultivating 20 hours at a temperature of 32° C. under shaking conditions of 110 rpm and 7 cm stroke, and providing a lactic acid concentration of at least 80 g/L of a fermentation liquor prepared by inoculating cells obtained by cultivating 20 hours under the above-described conditions, at an initial cell concentration of 36 g (on a dry cell weight basis)/L, into a 11.1% glucose aqueous solution, and then fermenting 3 hours at a temperature of 32° C. under shaking conditions of 110 rpm and 7 cm stroke. A method for producing lactic acid by using these transformants.

The present disclosure relates to a multi-enzyme conjugate, a method for preparing the same and a method for preparing an organic compound using the same. More particularly, a multi-enzyme conjugate exhibiting improved catalytic efficiency over respective free enzymes using site-specific incorporation of a clickable non-natural amino acid into the enzymes and two compatible click reactions, a method for preparing the same and a method for preparing an organic compound using the same may be provided.

Methods and materials related to producing isobutyric acid are disclosed. Specifically, isolated nucleic acids, polypeptides, host cells, methods and materials for producing isobutyric by direct microbial fermentation from a carbon source are disclosed.

Disclosed is a method of producing lactic acid using a recombinant acid-resistant yeast with inhibited lactate metabolism and alcohol production. More specifically, disclosed are a recombinant acid-resistant yeast in which lactate consumption reaction is reduced and which is imparted with lactic-acid-producing ability to thereby exhibit improved lactic-acid-producing ability and reduced ethanol production, and a method of producing lactic acid using the same.

The invention relates to a plastic compound comprising at least one polyolefin and a biological entity that degrades said polyolefin. The invention further relates to a process for preparing a plastic article wherein at least one polyolefin and one biological entity that degrades said polyolefin are mixed at a temperature at which the polyolefin is in a partially or totally molten state.

The present invention relates to: a novel Pichia kudriavzevii microorganism NG7 showing heat resistance and acid resistance; a composition, for producing organic acid or alcohol, which comprises the microorganism and a culture of the same; and a method, for producing an organic acid or alcohol, which comprises culturing the microorganism.

The invention relates to a genetically modified lactic acid bacterium capable of producing (S,S)-2,3-butanediol stereo specifically from glucose under aerobic conditions. Additionally the invention relates to a method for producing (S,S)-2,3-butanediol and L-acetoin using the genetically modified lactic acid bacterium, under aerobic conditions in the presence of a source of iron-containing porphyrin or a source of metal ions (Fe.sup.3+/Fe.sup.2+). The lactic acid bacterium is genetically modified to express heterologous genes encoding enzymes catalysing the stereo-specific synthesis of (S,S)-2,3-butandiol; and additionally a number of genes are deleted in order to maximise the production of (S,S)-2,3-butanediol as compared to other products of oxidative fermentation.

An object of the present invention is to obtain a fermentative yeast having a highly efficient ethanol production without introducing a foreign gene. A further object is to obtain a fermentative yeast that is resistant to proliferation inhibitors such as organic acids, which prevent the growth of the fermentative yeast. Yeast having improved ethanol production ability was generated by introducing transaldolase and alcohol dehydrogenase gene by self-cloning to Meyerozyma guilliermondii that can produce ethanol effectively from pentose and hexose obtained by breeding. This fermentative yeast is deposited to NITE Patent Microorganisms Depositary under the accession number NITE ABP-01976.

Disclosed is a microorganism, which has been engineered to acquire methylotrophy. More particularly, the application describes a non-naturally occurring microorganism, which has been engineered to express or include a first enzyme and a second enzyme, wherein the first enzyme is a methanol dehydrogenase (Mdh) enzyme or a methanol oxidase (Mox) enzyme, and wherein the second enzyme is a dihydroxyacetone synthase (Das) enzyme or a transketolase enzyme. The application also describes element and applications, more particularly kits and methods, which include or use the microorganism.