277 results about "Homoserine" patented technology

A composition comprising an amphoteric or pseudo-amphoteric agent and a polyhydroxy alpha hydroxyacid existing as a free acid, lactone, or salt, and isomeric or non-isomeric forms thereof is provided. The amphoteric or pseudo-amphoteric agent can be selected from amino acids, dipeptides, aminoaldonic acid, aminouronic acid, lauryl aminoproplyglycine, aminoaldaric acid, neuraminic acid desulfated heparin, deacetylated hyaluronic acid, hyalobiuronic acid, chondrosine, deacetylated chondroitin, creatine, creatinine, hydroxyproline, homocysteine, homocystine, homoserine, ornithine, citrulline, phosphatidylserine, and sphingomyelin. The composition may contain other additives, including cosmetic or pharmaceutical agents for topical treatment of dermatological disorders.

A bioactive food complex product, method for preparing a bioactive food complex product and method for controlling disease using probiotics and quorum sensing inhibitors such as inhibitory furanones and other bioactive compounds included in both the continuous and dispersed phases of a bioactive food complex product. The product is comprised of a solids-in-oil or an oil-in-solids emulsion forming a first emulsion that is itself emulsified in polymer forming oil-in-polymer or solids-in-polymer emulsion complex. The bioactive complex is formed of two emulsions with the first emulsion comprising the dispersed phase and a hydrocolloid polymer serving as the continuous phase. The second emulsion complex is then crosslinked to form a physically stable matrix. The bioactive food complex or the first emulsion of the bioactive food complex then serve to deliver different bioactive components including probiotic bacteria and quorum sensing inhibitor molecules to the digestive tract and environment of animals such as shrimp or fish or other livestock raised commercially to effectively control bacterial disease by a novel combination of mechanism including: competitive exclusion, direct inhibit, digestion of cell-to-cell signaling molecules and direct inhibition of homoserine lactone and (acyl) homoserine lactone regulated processes of pathogenic bacteria. Thus, effective disease prevention and control is accomplished through the novel combined delivery and use of probiotic bacteria and quorum sensing inhibitory furanones.

The invention belongs to the technical field of sewage treatment and relates to a method for enhancing aerobiotic ammonia oxidizing bacterium (AOB) gathering through N-acylated homoserine lactone (AHLs) compounds. The method includes the specific steps that AHLs signal molecules with the specific variety and the specific concentration are added to a reactor containing AOB activated sludge, under the condition that a sufficient nitrogen source and oxygen are provided, a quorum-sensing system is enhanced, aerobiotic ammonia oxidizing bacterium gathering growth is promoted, and biological membranes or granular sludge is obtained. According to the method, the AOB physiology is adjusted and controlled on the aspect of the signal molecules, AOB gathering growth is enhanced, rapid and efficient enrichment of AOB is achieved, and the AOB is fixed in a qualified sense, so that losses are reduced, and time needed for AOB enrichment is shortened. A new thought is provided for rapid AOB enrichment through the method, the method is expected to be used for the biological nitrogen removal process, and important significance is provided for efficient and stable operation of the ammonia-nitrogen wastewater biological treatment process.

The present invention provides compositions and methods for modulating the communication and virulence of quorum sensing bacteria. In various exemplary embodiments, the invention provides a combinatorial library of quorum sensing compounds including synthetic analogs of naturally occurring and non-naturally occurring acyl-homoserine lactone (AHL) analogs, and methods of synthesizing and using these compounds.

The present invention provides compounds and methods for modulation of the quorum sensing of bacteria. In an embodiment, the compounds of the present invention are able to act as replacements for naturally occurring bacterial quorum sensing ligands in a ligand-protein binding system; that is, they imitate the effect of natural ligands and produce an agonistic effect. In another embodiment, the compounds of the present invention are able to act in a manner which disturbs or inhibits the naturally occurring ligand-protein binding system in quorum sensing bacteria; that is, they produce an antagonistic effect. The compounds of the present invention comprise N-acylated-homoserine lactones (AHLs) comprised of a wide range of acyl groups.

The invention provides a quorum sensing quenching bacteria preparation method, a MBR membrane pollution prevention and control method, and a MBR membrane pollution prevention and control apparatus. The preparation method comprises: preparing an alternative strain having N-hexanoyl-homoserine lactone AHL decomposition and utilization capability from active sludge or sewage sampled from a sewage treatment plant; verifying the quorum sensing quenching ability of the alternative strain to screen quorum sensing quenching bacteria; and verifying the anti-bio-film ability of the quorum sensing quenching bacteria to obtain the effective quorum sensing quenching bacteria. According to the present invention, the prepared quorum sensing quenching bacteria uses the pollutants in the sewage as the nutrition to decompose other microorganisms during the growth process to generate the signal molecules, such that the concentration of the AHL signal molecules produced by other microorganisms in the membrane pool cannot achieve the concentration threshold required by the quorum sensing and the signal loop conduction cannot be formed so as to inhibit the bio-film formation of the membrane pool microorganisms on the MBR membrane assembly surface and achieve the effects of pollution prevention and energy consumption saving.

Amino acids such as threonine, homoserine, isoleucine, lysine, valine and tryptophan are produced using a bacterium belonging to the genus Escherichia which has been constructed from a sucrose non-assimilative strain belonging to the genus Escherichia and which harbors sucrose non-PTS or PTS genes and has an ability to produce the amino acid.

The invention relates to an environmentally-friendly method for synthesizing selenomethionine. The method comprises the following steps of: reducing alpha-amido-protected aspartate beta-alkyl grease into alpha-amido-protected homoserine, then carrying out acid catalysis for ring closing to obtain inner grease of the homoserine, then reacting with metal selenide to generate homocystine selenide, obtaining the alpha-amido-protected homoserine, and finally eliminating protection and obtaining a selenomethionine product. The environmentally-friendly method has the advantages that the highly-toxic and rotten dimethyl diselenide is prevented from being used, so that the damage to the environment and operators are greatly reduced; the yield is high, the production cost is lower, the product purity is high, and optical and pure selenomethionine can be produced by large batch; and the obtained product can be used for preparing the intermediate of a selenium-containing medicine, and solves the difficulty that the selenomethionine and the related medicines can not be popularized.

Disclosed is a strain of Escherichia sp., capable of producing O-acetyl homoserine in high yield, with the introduction and enhancement therein of the activity of: homoserine acetyl transferase, aspartokinase and homoserine dehydrogenase; and at least one enzyme selected from a group consisting of phosphoenolpyruvate carboxylase, aspartate aminotransferase and aspartate semi-aldehyde dehydrogenase. Also, a method of producing O-acetyl homoserine using the strain is provided.

The present invention relates to a microorganism producing L-methionine precursor, O-succinylhomoserine, 1) the homoserine O-succinyltransferase activity (EC2.3.1.46) is introduced and enhanced, wherein the homoserine O-succinyltransferase activity is feed back resistant to methionine; and 2) the aspartokinase or homoserine dehydrogenase activity (EC2.7.2.4 or 1.1.1.3) is enhanced, and a method of producing L-methionine precursor using the microorganism.

The present invention relates to a process for the production of methionine or its derivatives by culturing a microorganism in an appropriate culture medium comprising a source of carbon and a source of sulfur. The microorganism claimed is modified in a way that the production of cysteine and / or C1 units is enhanced and / or the transfer potential of the C1 units on 10 homocysteine is increased or optimized. The isolation of methionine or its derivates from the fermentation medium is also claimed.