Provided are a microorganism that produces a diamine compound and a method of producing a diamine compound.

The genetically modified microorganism expresses an enzyme involved in synthesis of a diamine compound, in which the diamine compound is represented by Formula: H.sub.2N—R—NH.sub.2 (wherein, R is a chain or cyclic organic group comprised of one or more atoms selected from the group consisting of C, H, O, N, and S), and the genetically modified microorganism is modified to reduce an activity of an alcohol dehydrogenase compared to a non-reduced strain.

A method for preparing a universal microbial medium by eutectic system-based cellulose liquefaction. The method includes: 1) mixing ionic liquid and cellulose, where the ionic liquid is preheated; 2) mixing a mixed solution I obtained in step 1) and distilled water; 3) filtering a mixed solution II obtained in step 2); and 4) diluting a filtrate obtained in step 3) with the distilled water to obtain the carbon source. A medium prepared from the carbon source can be used for culturing various microorganisms, with a desirable growth state of the microorganisms.

The present invention provides a recombinant cell for producing para-nitro-L-phenylalanine (pN-Phe). The recombinant cell comprises heterologous genes encoding heterologous enzymes. The recombinant cell expresses the heterologous enzymes and contains a native metabolite. The native metabolite is converted to the pN-Phe in the recombinant cell. The biosynthesized pN-Phe may be incorporated into a target polypeptide in the recombinant cell without requiring exposure of the recombinant cell to exogenous pN-Phe. A cell culture comprising the recombinant cell is also provided. Further provided is a method of producing pN-Phe by a recombinant cell comprising heterologous genes encoding heterologous enzymes. The method comprises expressing a native metabolite by the recombinant cell, expressing the heterologous enzymes, and converting the native metabolite to the pN-Phe in the recombinant cell. The method may further comprise incorporating the pN-Phe into the target polypeptide in the recombinant cell.

The present application relates to a fructose-4-epimerase variant exhibiting tagatose conversion activity and a method for preparing tagatose using the same.

An application of a branched-chain α-ketoacid dehydrogenase complex in preparation of malonyl coenzyme A. A method for preparing malonyl-CoA using a branched-chain α-ketoacid dehydrogenase complex, the method comprising introducing a gene encoding a branched-chain α-ketoacid dehydrogenase complex into a biological cell strain to obtain a recombinant cell strain capable of expressing the gene encoding the branched-chain α-ketoacid dehydrogenase complex; culturing the recombinant cell strain to prepare malonyl-CoA; the branched-chain α-ketoacid dehydrogenase complex is the following M1) or M2): M1) a set of proteins consisting of a bkdF protein, a bkdG protein, a bkdH protein and a lpdA1 protein; M2) a set of proteins consisting of a bkdA protein, a bkdB protein, a bkdC protein and the lpdA1 protein. Experimental results show that by using the branched-chain α-ketoacid dehydrogenase complex, not only malonyl-CoA can be prepared, but also a target product using malonyl-CoA as an intermediate product can further be prepared.

An amino acid sequence of the transaminase mutant is an amino acid sequence obtained by a mutation of an amino acid sequence is shown in SEQ ID NO: 1. The mutation occurred at least one of the following mutation sites: G17V, L36P, Q40H, G69Y, H70T, L73A, V77G, V77S, V77T, A78I, Y130M, Y130V, Y130T, N132I, N132T, K141S, K142S, K142T, R143P, G144F, G144W, G144Y, E145D, E145S, E145G, K146R, L148A, L148I and the like.

The present disclosure relates, according to some embodiments, to compositions, methods, systems, and kits for programmable endonucleolytic cleavage of DNA (e.g., ds DNA). For example, the in vitro activity of an Argonaute (e.g., a mesophilic Argonaute CbAgo from Clostridium butyricum) may be synchronized with DNA strand unwinding activity of a helicase (e.g., a nuclease deficient RecB.sup.exo-C DNA helicase from E. coli) for a rapid and efficient cleavage of double-stranded DNA targets. Enzymatic properties of CbAgo and different aspects of ds DNA cleavage were thoroughly explored by adapting high-throughput capillary electrophoreses technique for monitoring CbAgo cleavage activity in concurrence with RecB.sup.exo-C. The present disclosure shows that in the presence of RecB.sup.exo-C, CbAgo can be programmed with guides to cleave any site of interest localized at up to 10 kb distance from the end of linear ds DNA at 37° C. temperature. CbAgo/RecB.sup.exo-C can be programmed to generate DNA fragments flanked with unique single-stranded extensions suitable for seamless ligation with compatible DNA fragments. The present disclosure relates further the compositions, methods, systems, and kits for PRC-free assembly of linear DNA molecules by using CbAgo/RecB.sup.exo-C programmable DNA endonuclease. The results presented here demonstrate that the combination of CbAgo and RecB.sup.exo-C is currently an efficient mesophilic DNA-guided DNA-cleaving programmable endonuclease which can be used to prepare synthetic biology tools that require or benefit from sequence-specific nicking/cleavage of natural DNA at otherwise inaccessible locations.

Provided is a non-naturally occurring microorganism capable of producing cadaverine, wherein the microorganism is genetically modified to overexpress lysine decarboxylase and pyridoxal kinase. Also provided is a method for producing cadaverine by using such microorganism without adding external pyridoxal 5′-phosphate.

The present disclosure is directed to devices, instruments, and methods, including automated methods, for enhanced production and efficient screening of biosynthesized antibiotics. More particularly, the present disclosure provides for accelerated biosynthesis and screening on a single-cell scale.

Provided are a cAMP receptor protein variant, a microorganism including the same, and a method of producing an L-amino acid using the same.