An Escherichia coli-based kdtA-gene-modified recombinant strain, a construction method therefor and use thereof are provided. A mutant gene obtained by subjecting a wild-type kdtA gene (ORF sequence is shown in a sequence 73556-74833 in GenBank accession No. CP032667.1), a wild-type spoT gene (ORF sequence is shown in a sequence 3815907-3818015 in GenBank accession No. AP009048.1) and a wild-type yebN gene (ORF sequence is shown in a sequence 1907402-1907968 in GenBank accession No. AP009048.1) of an E. coli K12 strain and a derivative strain thereof (such as MG1655 and W3110) to site-directed mutagenesis, and a recombinant strain obtained therefrom can be used for the production of L-threonine. Compared with an unmutated wild-type strain, the obtained strain can produce L-threonine with a higher concentration and has good strain stability, and also has lower production cost as an L-threonine production strain.

The present invention relates to a strain deposited with the CNCM (Collection Nationale de Culture de Microorganismes, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France), under number CNCM I-5499. The present invention also relates to the in vitro use of strains for producing oligosaccharides and/or in a process for producing oligosaccharides.

The present invention finds an application, in particular in the bioproduction field, for example the production of compounds, for example of bio-compounds.

An adenosine-involved fully enzymatic synthesis method for NMN includes the steps under the same reaction system: (A) reacting, under the catalytic action of a yeast cell, adenosine, phosphate and sugar that is metabolizable by a yeast cell, so as to generate ATP; and (B) generating NMN by an enzymatic reaction including the step of under the action of NAMPT, reacting nicotinamide, PRPP and ATP to generate NMN, ADP and phosphate. In this way, a series of reactions such as the generation (regeneration) of ATP, the synthesis of NMN and the utilization of ATP are performed in one reaction system in a unified manner, and thus efficient synthesis of NMN can be implemented.

The present disclosure relates to a genetically engineered strain with high production of uridine and its construction method and application. The strain was constructed as follows: heterologously expressing pyrimidine nucleoside operon sequence pyrBCAKDFE (SEQ ID NO:1) on the genome of E coli prompted by strong promoter P.sub.trc to reconstruct the pathway of uridine synthesis; overexpressing the autologous prsA gene coding PRPP synthase by integration of another copy of prsA gene promoted by strong promoter P.sub.trc on the genome; deficiency of uridine kinase, uridine phosphorylase, ribonucleoside hydrolase, homoserine dehydrogenase I and ornithine carbamoyltransferase. When the bacteria was used for producing uridine, 40-67 g/L uridine could be obtained in a 5 L fermentor after fermentation for 40-70 h using the technical scheme provided by the disclosure with the maximum productivity of 0.15-0.25 g uridine/g glucose and 1.5 g/L/h respectively which is the highest level of fermentative producing uridine reported at present.

This disclosure provides mutant genes related to drug resistance and relapse of acute lymphoblastic leukaemia (ALL) and a use thereof, treatment or prevention of drug resistance and relapse of ALL and a use thereof, a use of compound Lometrexol and related inhibitors targeting GART and AITC in prevention and treatment of drug resistance and relapse of ALL, and a kit for evaluation of the risk of drug resistance and relapse of ALL. The mutation gene is a mutant gene of PRPS1. The drug acts on enzymes in purine synthesis pathway and reduces drug resistance and relapse by decreasing the concentration of hypoxanthine. The kit comprises reagents for lysis of sample cells and an instruction. The invention provides a powerful technical means and support for the prevention and treatment of drug resistance and relapse of ALL.

An object of the present invention is to provide a method for producing nicotinamide mononucleotide (NMN) with excellent production efficiency. The method for producing NMN according to the present invention (the first aspect) comprises the step of bringing a transformant with enhanced expression of enzymes nicotinamide phosphoribosyltransferase (Nampt), phosphoribosyl pyrophosphate synthetase (Prs) and polyphosphate kinase (Ppk), a cell-free protein synthesis reaction solution having the three enzymes expressed, or a treated product thereof into contact with a mixture containing ribose-5-phosphate (R5P), nicotinamide (NAM), ATP and polyphosphate.

Protein rupture under compressive forces can be regulated by cations. More specifically, pico-Newton forces can cause rupture of protein molecules, as shown in examples with calmodulin (CaM) and tau proteins, among others. However, rupture does not occur in the presence of various concentrations of cation(s), thus elucidating new targets for disease therapy and providing therapies for neurodegenerative diseases or other conditions involving protein misfolding, dysfunction, or aggregation.

The invention provides non-naturally occurring microbial organisms containing an alkene pathway having at least one exogenous nucleic acid encoding an alkene pathway enzyme expressed in a sufficient amount to convert an alcohol to an alkene. The invention additionally provides methods of using such microbial organisms to produce an alkene, by culturing a non-naturally occurring microbial organism containing an alkene pathway as described herein under conditions and for a sufficient period of time to produce an alkene.

The present invention relates to microbial production of nicotinamide mononucleotide (NMN), nicotinamide riboside (NR), and nicotinamide adenine dinucleotide (NAD) using a genetically modified bacterium.

The present invention relates to a tumor-targeting Salmonella gallinarum strain and the use thereof. The tumor-targeting Salmonella gallinarum strain has excellent tumor proliferation inhibitory activity and enables tumor-specific targeting, and thus can be utilized for treatment and imaging of tumors without any side effects.