The present disclosure provides mutated PglB oligosaccharyltransferase enzymes that have the ability to efficiently catalyze the transfer of a saccharide from a lipid carrier to an asparagine reissue in a glycosylation motif on a protein. Also provided are polynucleotides encoding the mutated PglB oligosaccharyltransferase enzymes, host cells capable of expressing the engineered PglB oligosaccharyltransferase enzymes, and methods of using the engineered PglB oligosaccharyltransferase enzymes to make N-glycosylated proteins. Also provided are N-glycosylated proteins that are made using the engineered PglB oligosaccharyltransferase enzymes.

Glucuronosyltransferase 1 gene which catalyzes glucuronic acid transfer to the hydroxyl group at the 3-position in an oleanane-type triterpenoid is identified. Glucuronosyltransferase 1 gene having a desired activity, derived from a Fabaceae plant (soybean, Glycyrrhiza, and Lotus japonicus), and containing nucleotide sequences represented by SEQ ID Nos: 2, 4, and 6, respectively, is provided.

Methods for recombinant production of steviol glycoside and compositions containing steviol glycosides are provided by this invention.

The disclosure is in the technical field of synthetic biology and metabolic engineering. The disclosure provides engineered viable bacteria. In particular, the disclosure provides viable bacteria with mutated outer membrane biosynthetic pathway leading to disruption of the pathway, preferably substantially lacking lipopolysaccharide (LPS, endotoxin) within the outer membrane. The disclosure further provides methods of generating viable bacteria and uses thereof. The disclosure also provides compositions and methods for inducing immune responses and for researching and developing therapeutic agents. Furthermore, the disclosure is in the technical field of fermentation of metabolically engineered microorganisms producing bioproduct or metabolite.

The present disclosure relates to Salmonella Gallinarum mutant strains and uses thereof. A vaccine composition according to an aspect has no risk of recovering pathogenicity, has no residual pathogenicity due to detoxification of an endotoxin, and does not cause lesions and bacterial re-isolation, thereby exhibiting significantly improved safety compared to the existing fowl typhoid vaccines. In addition, since the vaccine composition induces a high-level immune response even when administered to young chicks, it may be used regardless of age, and as the vaccine strain may be used as a live vaccine having an excellent protective capability by itself, the vaccine composition may be useful for preventing and alleviating fowl typhoid.

The invention discloses a recombinant Corynebacterium glutamicum for efficient synthesis of highly pure hyaluronic acid and oligosaccharides thereof, belonging to the technical field of bioengineering. The recombinant Corynebacterium glutamicum constructed in the present invention can produce hyaluronic acid with a yield up to 40g/L, and a crude product purity of 95%. Addition of exogenous hyaluronic acid hydrolase and optimization of the fermentation conditions results in hyaluronic acid oligosaccharides with specific molecular weight, and can further improve the yield of hyaluronic acid to 72 g/L. The invention lays a solid foundation for the efficient synthesis of highly pure hyaluronic acid by microorganisms, and the constructed recombinant Corynebacterium glutamicum is suitable for industrial production and application.

The disclosure relates to enzymes, such as cucurbitadienol synthase (CDS), UDP-glycosyltransferase (UGT), C11 hydroxylase, epoxide hydrolase (EPH), squalene epoxidase (SQE), and/or cytochrome P450 reductase enzymes, recombinant host cells expressing the enzymes, and methods of producing mogrol precursors, mogrol, and/or mogrosides using such recombinant cells.

Provided herein are enzymatic compositions for protein O-glycosylation and sialylation, methods and systems associated therewith. In particular, the composition for in vivo sialylation of therapeutic proteins. The composition comprises a polypeptide N-acetylgalactosaminyltransferase; a β-1,3-galactosyltransferase; an UDP-Glc/GlcNAc 4-epimerase; a disulfide bond isomerase; and an α-2,3-sialyltransferase or an α-2,6-sialyltransferase. Furthermore, provided herein are compositions for efficient and complete O-glycosylation and di-sialylation of therapeutic proteins.

Disclosed is a method for producing 3-fucosyllactose using a wild Corynebacterium glutamicum strain. In addition, using the Corynebacterium glutamicum strain, which is a GRAS strain, 3-fucosyllactose can be produced at a high concentration, high yield and high productivity.

The disclosure relates to methods and compositions for the production of fructans using sucrose:sucrose 1-fructosyl-transferase (1-SST), fructan:fructan 1-fructosyltransferase (1-FFT), and/or sucrose fructan-6-fructosyltransferase (6-SFT) enzymes.