A method is described for producing an L-amino acid including the steps of cultivating in a culture medium an L-amino acid-producing bacterium belonging to the family Enterobacteriaceae to produce and accumulate the L-amino acid in the culture medium, cells of the bacterium, or both, and collecting the L-amino acid from the culture medium, the cells, or both, wherein said bacterium has been modified to overexpress a gene encoding a periplasmic adaptor protein.

A method of the bio-production of methionine and/or of its derivatives thereof from a reduced source of sulfur, such as MeSH or MeSNa including genetically modified yeasts, having an increased ability to produce methionine and/or its derivatives thereof, as compared to the parent yeasts.

A method of the bio-production of methionine and/or of its derivatives thereof from a reduced source of sulfur, such as MeSH or MeSNa including genetically modified yeasts, having an increased ability to produce methionine and/or its derivatives thereof, as compared to the parent yeasts.

The present disclosure relates to a novel O-phosphoserine export protein, and a method for producing O-phosphoserine, cysteine, and cysteine derivatives using the same.

The present disclosure relates to a novel O-phosphoserine export protein, and a method for producing O-phosphoserine, cysteine, and cysteine derivatives using the same.

The present invention relates to a process for synthesizing functionalized mercaptans essentially in the absence of oxygen, and also to a composition making it possible in particular to implement this process. Said functionalized mercaptans are of the following formula (I):

##STR00001##

in which, R.sub.1 and R.sub.7, which are identical or different, are a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; X is chosen from -C(=O)-, -CH.sub.2- or -CN; R.sub.2 is: (i) either absent when X represents -CN, (ii) or a hydrogen atom, (iii) or -OR.sub.3, R.sub.3 being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms, (iv) or -NR.sub.4R.sub.5, R.sub.4 and R.sub.5, which are identical or different, being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; n is equal to 1 or 2; and * represents an asymmetric carbon.

The present invention relates to a process for synthesizing functionalized mercaptans essentially in the absence of oxygen, and also to a composition making it possible in particular to implement this process. Said functionalized mercaptans are of the following formula (I):

##STR00001##

in which, R.sub.1 and R.sub.7, which are identical or different, are a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; X is chosen from -C(=O)-, -CH.sub.2- or -CN; R.sub.2 is: (i) either absent when X represents -CN, (ii) or a hydrogen atom, (iii) or -OR.sub.3, R.sub.3 being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms, (iv) or -NR.sub.4R.sub.5, R.sub.4 and R.sub.5, which are identical or different, being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; n is equal to 1 or 2; and * represents an asymmetric carbon.

The present invention provides a method for producing an L-amino acid such as a branched-chain L-amino acid by fermentation using a bacterium of the family Enterobacteriaceae, particularly a bacterium belonging to the genus Escherichia, which has been modified to attenuate expression of the gshA gene.

The present invention provides a method for producing an L-amino acid such as a branched-chain L-amino acid by fermentation using a bacterium of the family Enterobacteriaceae, particularly a bacterium belonging to the genus Escherichia, which has been modified to attenuate expression of the gshA gene.

The present invention relates to a novel black garlic extract using garlic bulbs separated into six bulbs as a raw material instead of conventional whole garlic and a preparation method thereof. There is an excellent effect of providing a novel black garlic extract with various functionalities of high sweetness and high viscosity and improved flavor and reddish brown color as well as induce high-concentration conversion of 10 times or more to a S-allyl-cysteine compound in which a functional ingredient of raw garlic having antioxidation, reduction in blood cholesterol, improved liver function, and enhanced blood pressure is present in a small amount of 10 ppm or less by maximizing conversion of starch into reducing sugar for most preferably 15 days in a 90% to 100% saturated steam state and a liquefied enzymatic action temperature of 75° C. to 80° C. or lower without separate enzyme addition, and optimizing the action of proteases.