The invention refers to standardized plant extract from biomass of in vitro cultures of Haberlea rhodopensis Friv. (HR), containing bioactive compounds and their primary secondary metabolites, containing in weight %, as follows: organic acid from 4.0 to 6.0, fatty acids from 0.5 to 1.5, amino acids from 8.0 to 12.0, sterols from 0.5 to 1.0, free phenols from 3.0 to 6.0, sugars from 45 to 55, and polyphenols from 25.0 to 35.0, with a predominant myconoside content of 70% to 96% in the polyphenolic fraction, constituting 18% to 35% of the total extract, and to a composition containing the standardized extract and glycerol as well as to a method for the preparation of a standardized plant extract.

The method according this invention, along with its optimally chosen steps, specific conditions, parameters such as temperature, duration, stirring, light, growth factors, etc. achieves both maximum volumetric productivity of the target substances and myconoside, as well as stable productivity of the plant in vitro cultures and is a reliable efficient 24/7 continuous system for production of NPs.

Dependence on natural factors, limited availability and protection of HR rare wild plant populations are eliminated. The limitations posed by seasonality and slow HR growth are also avoided by developing a renewable, ecologically method. The developed method provides alternative, renewable and sustainable sources of raw plant material necessary to obtain the target extract. The resulting extract standardized in myconoside is especially valuable with its protective action on human health and can successfully be used with its pharmacological, cosmetic effects as well as in functional foods.

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 in the present invention is an L-glutamate dehydrogenase mutant, the sequence of the L-glutamate dehydrogenase mutant being a sequence in which amino acid residue A at position 175 in SEQ ID NO: 1 is mutated to be G, and amino acid residue V at position 386 is mutated to be an amino acid residue having less steric hindrance. Further disclosed in the present invention is an application of the described L-amino acid dehydrogenase mutant in the preparation of L-glufosinate-ammonium or a salt thereof. When the L-glutamate dehydrogenase mutant of the present invention is used to prepare L-glufosinate-ammonium or a salt thereof, compared to an L-glutamate dehydrogenase mutant in which only position 175 or 386 is mutated, the specific enzyme activity is higher. Therefore, the action efficiency of the enzyme is improved, reaction costs are reduced, and industrial production is facilitated.

Disclosed in the present invention is an L-glutamate dehydrogenase mutant, the sequence of the L-glutamate dehydrogenase mutant being a sequence in which amino acid residue A at position 175 in SEQ ID NO: 1 is mutated to be G, and amino acid residue V at position 386 is mutated to be an amino acid residue having less steric hindrance. Further disclosed in the present invention is an application of the described L-amino acid dehydrogenase mutant in the preparation of L-glufosinate-ammonium or a salt thereof. When the L-glutamate dehydrogenase mutant of the present invention is used to prepare L-glufosinate-ammonium or a salt thereof, compared to an L-glutamate dehydrogenase mutant in which only position 175 or 386 is mutated, the specific enzyme activity is higher. Therefore, the action efficiency of the enzyme is improved, reaction costs are reduced, and industrial production is facilitated.

Provided is a novel production system for a product selected from a nitrogen-containing product and a fermented and cultured product that does not involve (or can minimize) the transport of liquid ammonia. A production system for a product selected from a nitrogen-containing product and a fermented and cultured product can include: an ammonia synthesis apparatus in which an ammonia-containing gas is synthesized by reaction of a source gas containing hydrogen and nitrogen in the presence of a supported metal catalyst containing as a support one or more selected from the group consisting of: i) a conductive mayenite compound; ii) a two-dimensional electride compound or a precursor thereof; and iii) a complex formed of a support base containing at least one metal oxide selected from ZrO.sub.2, TiO.sub.2, CeO.sub.2, and MgO and a metal amide represented by a formula M(NH.sub.2).sub.x (where M represents one or more selected from Li, Na, K, Be, Mg, Ca, Sr, Ba, and Eu; and x represents a valence number of M) supported by the support base; and a production apparatus that produces a product selected from a nitrogen-containing product and a fermented and cultured product using ammonia originating from the ammonia-containing gas obtained by using the ammonia synthesis apparatus.

The invention relates to nitrilases and to nucleic acids encoding the nitrilases. In addition methods of designing new nitrilases and method of use thereof are also provided. The nitrilases have increased activity and stability at increased pH and temperature.

The invention relates to nitrilases and to nucleic acids encoding the nitrilases. In addition methods of designing new nitrilases and method of use thereof are also provided. The nitrilases have increased activity and stability at increased pH and temperature.

The present disclosure provides methods for preparing β-substituted tryptophan compounds. The methods include: combining i) an unsubstituted indole or a substituted indole, ii) a β-substituted serine, and iii) a tryptophan synthase β-subunit (i.e., a TrpB); and maintaining the resulting mixture under conditions sufficient to form the β-substituted tryptophan. The TrpB contains at least one amino acid mutation which promotes formation of an amino-acrylate intermediate. New TrpB variants and new β-substituted tryptophan analogs are also described.

The present disclosure provides methods for preparing β-substituted tryptophan compounds. The methods include: combining i) an unsubstituted indole or a substituted indole, ii) a β-substituted serine, and iii) a tryptophan synthase β-subunit (i.e., a TrpB); and maintaining the resulting mixture under conditions sufficient to form the β-substituted tryptophan. The TrpB contains at least one amino acid mutation which promotes formation of an amino-acrylate intermediate. New TrpB variants and new β-substituted tryptophan analogs are also described.

The present invention belongs to the field of microbial technology, and specifically relates to a strain of Hericium erinaceus HT-3, with a deposit number of CCTCC No: M 2018567. The present invention also relates to a screening method for Hericium erinaceus HT-3. The screening method comprises the steps of purifying the strain of Hericium erinaceus from a tissue block, fermenting and culturing the strain, soak extracting ergothioneine from the mycelium cells in the fermentation broth, detecting the ergothioine content in the fermentation broth. The Hericium erinaceus strain screened according to the present invention has high ergothioneine yield, and the screening method is simple in process, easy to be operated, and low in production cost.