The present disclosure relates to a variant of cAMP receptor protein of Escherichia coli with alanine at position 35, a microorganism including the same, and a method of producing an L-amino acid using the same.

Provided are a novel fructose-C4-epimerase and a method of producing tagatose using the same.

Described is a method for the incorporation of formaldehyde into biomass comprising the following enzymatically catalyzed steps (1) condensation of pyruvate with formaldehyde into 4-hydroxy-2-oxobutanoic acid (HOB); (2) amination of the thus produced 4-hydroxy-2-oxobutanoic acid (HOB) to produce homoserine; (3) conversion of thus produced homoserine to threonine; (4) conversion of the thus produced threonine into glycine and acetaldehyde or acetyl-CoA; (5) condensation of the thus produced glycine with formaldehyde to produce serine; and (6) conversion of the thus produced serine to produce pyruvate, wherein said pyruvate can then be used as a substrate in step (1).

The disclosure discloses a method for efficient biosynthesis of Reb D by glycosyltransferase, belonging to the field of biocatalytic synthesis. According to the disclosure, a glycosyltransferase having an activity to catalyze synthesis of Reb D from Reb A is obtained, and a mutant YojK-I241T/G327N with high catalytic activity is obtained through directed evolution. The glycosyltransferase mutant YojK-I241T/G327N and a sucrose synthase AtSuSy derived from Arabidopsis thaliana are used for constructing a coupling reaction to realize efficient catalytic synthesis of Reb D with Reb A as a substrate. The reaction is carried out by using 19.32 g/L (20 mmol/L) of Reb A as the substrate for 15 h to efficiently synthesize 20.59 g/L of Reb D, and the yield of Reb D reaches 91.29%, which provides an efficient and green new pathway for production of Reb D.

A genetically engineered bacterium includes a genome of the Eschericia coli and a mutant encoding gene hisG* of a Corynebacterium glutamicum ATP phosphoribosyl transferase HisG on the genome, and the gene hisG* is strongly expressed to enhance activity of a key enzyme HisG for histidine synthesis. The gene hisG* has a nucleotide sequence as shown in SEQ ID NO: 1; a copy number of histidine operon genes hisDBCHAFI of the Eschericia coli is further increased on the genome to enhance a terminal synthetic route of histidine; an encoding gene lysE from an arginine/lysine transportprotein of the Corynebacterium glutamicum is further integrated to the genome and strongly expressed to promote the intracellular histidine secrete to the extracellular space; and an encoding gene rocG of glutamate dehydrogenase of Bacillus subtilis is further integrated to the genome and strongly expressed to promote generation of histidine.

Disclosed are methods, systems, components, and compositions for cell-free synthesis of glycosylated proteins. The glycosylated proteins may be utilized in vaccines, including anti-bacterial vaccines. The glycosylated proteins may include a bacterial polysaccharide conjugated to a carrier, which may be utilized to generate an immune response in an immunized host against the polysaccharide conjugated to the carrier. The glycosylated proteins may be synthesized in cell-free glycoprotein synthesis (CFGpS) systems using prokaryote cell lysates that are enriched in components for glycoprotein synthesis such as oligosaccharyltransferases (OSTs) and lipid-linked oligosaccharides (LLOs) including OSTs and LLOs associated with synthesis of bacterial O antigens.

Provided is a method for producing 1,3-propanediol by means of fermentation of a recombinant microorganism. First, a recombinant microorganism is provided; the recombinant microorganism can overexpress acetyl-CoA carboxylase genes: accBC and accDA, a malonyl-CoA synthetase gene: mcr, a 3-hydroxypropionyl-CoA synthetase gene: pcs, a 3-hydroxypropionyl-CoA reductase gene: pduP, and a 1,3-propanediol reductase gene: yqhD. The recombinant microorganism is subjected to fermentation culture in a flask or fermentor using glucose ad as raw material to obtain the 1,3-propanediol. The recombinant microorganism can utilize low-cost glucose, sucrose, molasses, xylose and the like as raw material in the fermentation process, without additional expensive vitamin B12. Thus, cost of the production is significantly reduced, and there is a promising prospect in market.

A transport protein coding gene, and a method for efficient production of L-tryptophan by a strain containing the gene. Specifically, by heterologous expression of ywkB gene from Bacillus subtilis on the genome of Escherichia coli, L-tryptophan production efficiency of the strain can be improved. Performing shake flask fermentation with the strain can accumulate 15.2 g/L of L-tryptophan within 24 h, which is 35% higher than a control strain.

Disclosed are gene engineering bacteria for producing L-arginine and a construction method and an application of the gene engineering bacteria. According to the method, genes encoding a carbamoyl phosphate synthetase and a gene encoding an L-arginine biosynthesis pathway enzyme are integrated into Escherichia coli; the present invention has analyzed and reconstructed the arginine synthetic pathway and the metabolic flow related to arginine in the entire amino acid metabolic network in E. coli and finally obtained a genetically engineered bacterial strain which has a clear genetic background, carries no plasmids, undergoes no mutagenesis and is capable of stably and efficiently producing L-arginine.

Improved production of recombinant proteins in E. coli, reliant on tightly controlled autoinduction, triggered by phosphate depletion in stationary phase. The process also provides an optimized autoinduction media, enabling routine batch production at various culture volumes where cells densities routinely reach ˜5-7 g cell dry weight per liter and offer protein titers above 2 g/L. The methodology has been validated with a set of diverse heterologous proteins and is of general use for the facile optimization of routine protein expression from high throughput screens to fed-batch fermentation.