The disclosure relates to engineered ketoreductase polypeptides and processes of using the polypeptides for production of phenylephrine.

Provided are methods for synthesizing compounds, including chiral kynurenine compounds. The methods are suitable for large-scale manufacture and produce the chiral kynurenines compounds in high chemical purity and high chiral purity.

Disclosed are transformed cells and related nucleotide and protein sequences, and fermentation compositions and methods, all of which are related to providing selective advantage in fermentation. For example, a selective advantage results from transformation of a cell with a nucleic acid that allows a transformed cell to metabolize one or more nitrogen-, phosphorous-, and/or sulfur-containing compounds that a native cell of the same species as the transformed cell cannot metabolize, and from fermentation of the transformed cell using one or more feedstocks, such as fractioned grain, which are depleted in or free of conventional nitrogen-, phosphorous-, and/or sulfur-containing compounds that a native cell of the same species as the transformed cell can metabolize. Also disclosed are methods for improved oxygen transfer in an aerobic or microaerobic fermentation.

The invention relates to acetylcholine-producing microorganisms for use in the prevention and/or treatment of intestinal diseases, and/or reduction of risks of intestinal diseases, and/or improvement of intestinal health as well as promoting healthy gut flora. The acetylcholine-producing microorganisms may be provided as a pharmaceutical dosage form or as additive to functional food or food supplemental products. Also encompassed is a method for the production of acetylcholine by use of Lactobacilli. Further the invention refers to microbially produced acetylcholine for use in the treatment and/or prevention of intestinal diseases.

The present application provides engineered polypeptides having imine reductase activity, polynucleotides encoding the engineered imine reductases, host cells capable of expressing the engineered imine reductases, and methods of using these engineered polypeptides with a range of ketone and amine substrate compounds to prepare secondary and tertiary amine product compounds.

Disclosed in the present disclosure are methods for enzymatic production of glucosamine salts and the purification methods thereof, and belongs to the technical field of biological engineering. In the present disclosure, liquid containing N-acetylglucosamine is used as a raw material, subjected to hydrolysis with deacetylase to obtain glucosamine and acetic acid, and followed by elution on a cation exchange column with an acidic eluent and separation to obtain the glucosamine salt. Meanwhile, a by-product, namely sodium acetate, is recovered by anion exchange. The obtained glucosamine salt is subjected to concentration, crystallization, decolorization, and drying to obtain a high-purity glucosamine salt crystal. According to the present disclosure, processes for recycling of an enzyme, a residual substrate, and acetic acid are combined. Moreover, the loss rate of resin is low under operation conditions at room temperature, and the production of a hydrochloric acid waste liquid is extremely low.

One aspect provided herein relates to lysine decarboxylase polypeptides comprising mutants of SEQ ID NO: 2 (i.e., mutants of Klebsiella oxytoca (K. oxytoca) Ldc) and/or fragments thereof. In certain embodiments, the mutants or fragments thereof may have at least about 95% sequence identity with SEQ ID NO: 2. Another aspect provided herein relates to a DNA polynucleotide comprising one or more lysine decarboxylase nucleotide sequences of mutants of SEQ ID NO: 1 (i.e., mutants of K. oxytoca ldc), fragments thereof, or fragments of SEQ ID NO: 1 (i.e., fragments of K. oxytoca ldc). In certain embodiments, the DNA polynucleotide as disclosed herein may encode one or more lysine decarboxylase polypeptides provided herein. In certain embodiments, the DNA polynucleotide as disclosed herein may encode SEQ ID NO: 2, mutants, and/or fragments thereof. In certain embodiments, the lysine decarboxylase nucleotide sequences provided herein may have at least 95% sequence identity with SEQ ID NO: 1 or SEQ ID NO: 3. Another aspect provided herein relates to expression vectors comprising the DNA polynucleotides described herein used for production of a lysine-derived product. Other aspects provided herein include transformants, mutant host cells, methods for the production of lysine decarboxylases, and methods for the production of a lysine-derived product.

Disclosed are a variety of amphoteric compounds containing a quaternary nitrogen group, a covalently bound counterion, and an ester or amide group. These amphoteric compounds can be advantageously prepared via a chemoenzymatic green process, and exhibit good surfactant properties.

Disclosed are transaminase (TA) enzymes and nucleic acids encoding them. In some cases, the transaminase enzymes are non-natural, engineered transaminases. Also disclosed are biosynthetic methods and engineered microorganisms that enhance or improve the biosynthesis of 6-aminocaproate, hexamethylenediamine, caproic acid, caprolactone, or caprolactam. The engineered microorganisms include exogenous TA and in some cases engineered TA.

Host cells that are engineered to produce benzylisoquinoline alkaloid (BIAs) precursors, such as norcoclaurine (NC) and norlaudanosoline (NL), are provided. The host cells may have one or more engineered modifications selected from: a feedback inhibition alleviating mutation in a enzyme gene; a transcriptional modulation modification of a biosynthetic enzyme gene, an inactivating mutation in an enzyme; and a heterologous coding sequence. Also provided are methods of producing a BIA of interest or a precursor thereof using the host cells and compositions, e.g., kits, systems etc., that find use in methods of the invention.