The present invention relates to alpha-amylase variants having an improved stability as compared to the parent alpha-amylase. The invention further relates to use of the variants, compositions comprising the variants, and methods of producing the variants.

The disclosure relates to a sucrose phosphorylase mutant with improved enzyme activity, and construction method thereof and use thereof, and belongs to the technical field of genetic engineering. The amino acid sequence of the mutant of the disclosure is as shown in SEQ ID NO: 1. The mutant of the disclosure is based on sucrose phosphorylase derived from Leuconostoc mesenteroides, and subjected to site-directed mutagenesis to improve the enzyme activity of sucrose phosphorylase. The mutant is expressed in Corynebacterium glutamicum and used as a whole cell catalyst to produce 2-O-α-D-glycerol glucoside. At a 5 L fermentation tank level, a large quantity of 2-O-α-D-glycerol glucoside can be produced efficiently in a short time, which is conducive to expanding the prospect of industrial application of sucrose phosphorylase for the production of 2-O-α-D-glycerol glucoside and realizing its large-scale industrial application.

The present invention relates to a recombinant microorganism having an enhanced ability to produce heme, coproporphyrin III (Copro III), and uroporphyrin III (Uro III), and a method for producing heme, coproporphyrin III, and uroporphyrin III using same. When using a recombinant microorganism incorporating a gene that codes glutamyl-tRNA reductase (HemA), glutamate-1-semialdehyde aminotransferase (HemL), and diphtheria toxin repressor (DtxR), which is a transcription factor capable of inducing the expression of genes related to heme metabolic pathways, porphyrin-based structures can be produced at high yield, and thus the method is economic.

Disclosed are recombinant host cells comprising a promoter-effective nucleic acid molecule operably coupled to a nucleic acid molecule that encodes a plant effector protein or polypeptide that induces an active plant response including, among others, growth enhancement, disease resistance, pest or insect resistance, and stress resistance. Use of these recombinant host cells for modulating plant biochemical signaling, imparting disease resistance to plants, enhancing plant growth, imparting tolerance to biotic stress, imparting tolerance and resistance to abiotic stress, imparting desiccation resistance to cuttings removed from ornamental plants, imparting post-harvest disease or post-harvest desiccation resistance to a fruit or vegetable, or enhancing the longevity of fruit or vegetable ripeness are also disclosed.

The present disclosure discloses a genetically engineered strain, belonging to the technical field of bioengineering. L-amino acid oxidase genes, α-keto acid decarboxylase genes, alcohol dehydrogenase genes, and enzyme genes capable of reducing NAD(P) to NAD(P)H are introduced into the genetically engineered strain of the present disclosure. The present disclosure further discloses a construction method and application of a recombinant Escherichia coli genetically engineered strain. When being applied to the biosynthesis of phenylethanoids, the method of the present disclosure has the characteristics of simple operation, low cost, and high synthesis efficiency and optical purity of the product, and has good industrialization prospects.

The present invention relates to an isolated polypeptide having beta-lactamase activity and nucleic acid sequences encoding the polypeptide. The isolated polypeptide of the invention is a VIM-2 variant with improved properties such as improved protease stability, stability in intestinal medium, improved activity against one or more antibiotics, improved specific activity and/or improved production in a host cell.

Methods of treating individuals with a glucose metabolism disorder and/or a body weight disorder, and compositions associated therewith, are provided.

The invention provides a genetically modified micro-organism for intracellular biosynthesis of a cellular metabolite, comprising a synthetic error correction system having a penalty gene, whose expression leads to arrested growth or cell death (e.g. a toxin gene) in combination with a survival gene, whose expression provides an antidote that restores cell viability and normal growth (e.g. a cognate antitoxin gene). Alternatively, the system has a survival gene, alone, whose expression is essential for growth (i.e. essential gene). The synthetic error correction system further comprises a biosensor, whose function is to induce expression of the survival gene which leads to cell growth, only, when the cell produces a pre-defined level of a given metabolite. The invention further encompasses: a method for producing the genetically modified micro-organism; a method for producing a cellular metabolite with the genetically modified micro-organism; and use of the genetically modified micro-organism for producing a cellular metabolite.

The present disclosure provides recombinant microorganisms and methods for the production of 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA from a carbon source. The method provides for engineered microorganisms that express endogenous and/or exogenous nucleic acid molecules that catalyze the conversion of a carbon source into 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA. The disclosure further provides methods of producing polymers derived from 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA.

α2-6-Sialyltransferase (2,6ST) variants having improved α2-6-specific sialidase activity as compared to the native 2,6ST enzymes are described. The variants include GT80 sialyltransferases such as P. damselae Pd2,6ST. Methods for making de-sialylated products and screening sialidase activity are also described.