Provided is a glycosyltransferase UGTSL2 mutant, which is produced through any one or more selected from the group consisting of mutations based on an amino acid sequence shown in SEQ ID NO: 1. Also provided is a glycosyltransferase mutant, which is the following A1) or A2): A1) a protein produced through an amino acid residue substitution in an amino acid sequence shown in SEQ ID NO: 66, where the protein has an identity of 90% or more with and the same function as the amino acid sequence shown in SEQ ID NO: 66; and A2) a fusion protein produced by linking a tag to an N-terminus and/or a C-terminus of the protein in the A1).
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
C12N 15/70 - Vecteurs ou systèmes d'expression spécialement adaptés à E. coli
C12P 19/18 - Préparation de composés contenant des radicaux saccharide préparés par action d'une transférase glycosylique, p. ex. alpha-, bêta- ou gamma-cyclodextrines
2.
METHOD FOR PREPARING GLUCOSYL STEVIOSIDE USING MOTHER LIQUOR SUGAR, SEPARATING AND PURIFYING GLUCOSYL STEVIOSIDE AND RECOVERING GLUCOSE
The present invention belongs to the technical field of food additives. A method for preparing glucosyl stevioside using a mother liquor sugar, separating and purifying the glucosyl stevioside and recovering glucose. Provided is a method for preparing glucosyl stevioside using a mother liquor sugar. By taking a mother liquor sugar as a raw material to prepare glucosyl stevioside, the route of utilization of mother liquor sugars is enriched, the technical gap of preparing glucosyl stevioside using a mother liquor sugar as a raw material is filled, and the prepared product has the advantages of good mouthfeel and high total glycoside content. Provided is a method for purifying glucosyl stevioside, wherein dextrin is recycled, which reduces the discharge of waste liquid, greatly reduces the energy consumption and cost of production, and improves the yield of glucosyl stevioside with high purity. Further provided is a method for separating and purifying glucosyl stevioside and recovering glucose, which method is simple in terms of process and easy to operate, and can not only obtain glucosyl stevioside with high purity, but also recycle unreacted substrates so as to reduce the cost.
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
C12P 19/18 - Préparation de composés contenant des radicaux saccharide préparés par action d'une transférase glycosylique, p. ex. alpha-, bêta- ou gamma-cyclodextrines
C12P 19/14 - Préparation de composés contenant des radicaux saccharide préparés par action d'une carbohydrase, p. ex. par action de l'alpha-amylase
C12P 19/22 - Préparation de composés contenant des radicaux saccharide préparés par action d'une bêta-amylase, p. ex. maltose
Provided is a glycosyltransferase UGTSL2 mutant. Said UGTSL2 mutant is obtained by means of any one or more of the following mutations on an amino acid sequence shown as SEQ ID NO. 1: the 23rd amino acid is mutated from N to E; the 41st amino acid is mutated from R to P; the 91st amino acid is mutated from H to K; the 95th amino acid is mutated from K to D; the 123rd amino acid is mutated from E to P; the 136th amino acid is mutated from L to F; the 151st amino acid is mutated from R to F; the 124th amino acid is mutated from H to E; the 168th amino acid is mutated from V to Y; the 198th amino acid is mutated from C to K; the 202nd amino acid is mutated from T to E; the 217th amino acid is mutated from W to K; the 225th amino acid is mutated from P to L; the 226th amino acid is mutated from F to V; the 285th amino acid is mutated from A to V; the 333rd amino acid is mutated from I to V, etc. Also provided is a glycosyltransferase mutant, the glycosyltransferase mutant being following A1) or A2): A1) being a protein which is obtained by means of substitution of an amino acid residue on an amino acid sequence shown as SEQ ID NO. 66, and which has 90% or higher identity with and same functions as the original protein, and A2) being a fusion protein obtained by linking a tag to the N-terminal and/or the C-terminal of A1.
C12N 15/70 - Vecteurs ou systèmes d'expression spécialement adaptés à E. coli
C12N 1/21 - BactériesLeurs milieux de culture modifiés par l'introduction de matériel génétique étranger
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
C12P 19/18 - Préparation de composés contenant des radicaux saccharide préparés par action d'une transférase glycosylique, p. ex. alpha-, bêta- ou gamma-cyclodextrines
4.
METHOD EMPLOYING COMPOSITE CHITOSAN FLOCCULATION TO PREPARE STEVIA POLYPHENOL
Disclosed are a method employing composite chitosan flocculation to prepare stevia polyphenol and stevia polyphenol prepared by the method. The method comprises: flocculating a stevia leaf water extract with a composite chitosan at room temperature to remove impurities, and adsorbing the supernatant with a macroporous polar resin, wherein the effluent is to be further used for the extraction of stevioside; eluting the resin with aqueous alcohol solutions of different concentrations, and after elution with a low-concentration aqueous alcohol solution, combining the resultant separated solution with the effluent produced before separation to obtain a combined solution, the total phenol content in the combined solution being less than 0.5% (on a dry basis), and the combined solution being reserved for extraction of stevioside; and drying the eluent produced from elution with a high-concentration aqueous alcohol solution, to give stevia polyphenol mainly composed of isochlorogenic acid.
A method for preparing a glucosyl steviol glycoside having a small number of grafts, relates to performing catalytic hydrolysis on a glucosyl steviol glycoside having a large number of grafts by means of an amylase to prepare a glucosyl steviol glycoside having a small number of grafts, wherein in the glucosyl steviol glycoside having a small number of grafts, the content of monoglucosyl and diglucosyl substituents of the steviol glycoside is 60% or more of the total glycosides, and the mass percentage of the glucosyl steviol glycoside with the number of glucosyl grafts being 3 or less is totally 70% or more of the total glycosides; the total glycosides comprise the glucosyl steviol glycoside and a steviol glycoside. Also provided are a product of glucosyl steviol glycoside having a small number of grafts prepared by the method, a sweetener or a corrigent comprising the product, an application of the product in preparation of a sweetener or a corrigent, a food, a drink, or flavoring comprising the product, and an application of the product in preparation of a food, a drink, or flavoring.
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
C12P 19/14 - Préparation de composés contenant des radicaux saccharide préparés par action d'une carbohydrase, p. ex. par action de l'alpha-amylase
C12P 19/18 - Préparation de composés contenant des radicaux saccharide préparés par action d'une transférase glycosylique, p. ex. alpha-, bêta- ou gamma-cyclodextrines
C12P 19/22 - Préparation de composés contenant des radicaux saccharide préparés par action d'une bêta-amylase, p. ex. maltose
6.
Method for the preparation of lower graft degree glucosylated steviol glycosides
The present invention discloses a method for preparing lower graft degree GSGs, and belongs to the technical field of biosynthesis of sweeteners. The method uses amylase to catalyze hydrolysis of GSGs with a high graft degree, thereby obtaining GSGs with low graft degree mainly containing GSGs with a low grafting number. The content of mono- and di-glucosyl substituents in the SGs in the product was 60% or more of the total glycosides, and the mass percent of the GSGs with a glucosyl grafting number of 3 or less was higher than 70% of the total glycosides. The mono- and di-substituted GSGs obtained by enzyme catalysis by the present invention were structurally similar to those, belong to a mixture of the isomers thereof, and have good sweetness and a flavoring function.
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
C12N 9/28 - Alpha-amylase d'origine microbienne, p. ex. amylase bactérienne
C12N 9/26 - Hydrolases (3.) agissant sur les composés glycosyliques (3.2) agissant sur les liaisons alpha-glucosidiques-1, 4, p. ex. hyaluronidase, invertase, amylase
7.
High-throughput enzymatic preparation of glucosylated steviol glycosides under programming temperatures
Geobacillus sp. as a catalyst, steviol glycosides as the glycosyl receptor and dextrin or oligosaccharide as the glycosyl donor, taking a calcium/barium ion salt bridge as the main stabilizer and combining with glycerol to adjust the conformation and binding domain openness of the enzyme, and utilizing transglucosylation and hydrolytic activities of amylase at variable temperatures in different stages, thereby preparing the glucosyl steviol glycosides through enzymatic catalysis under programming temperatures in high throughput. The technology of the present invention can improve the utilization rate of the enzyme, and obtain glucosyl steviol glycosides with good sweetness and good taste.
C12P 19/18 - Préparation de composés contenant des radicaux saccharide préparés par action d'une transférase glycosylique, p. ex. alpha-, bêta- ou gamma-cyclodextrines
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
8.
METHOD FOR PREPARING GLUCOSE-BASED STEVIOSIDE IN ENZYMATIC VARIABLE TEMPERATURE AND HIGH THROUGHPUT
The present invention relates to the technical field of sweetener biosynthesis, and provides a method for preparing glucose-based stevioside in enzymatic variable temperature and high throughput. According to the present invention, cyclodextrin glucosyltransferase derived from Geobacillus sp. is used as a catalyst, stevioside is used as a glycosyl receptor, dextrin or oligosaccharide is used as a glycosyl donor, and a calcium barium ion salt bridge is used as a main stabilizer, and glycerol is combined with to adjust the conformation and binding domain opening degree of enzyme, the variable temperature utilizes the transesterification and hydrolysis activity of amylase by stages to prepare the glucose-based stevioside in enzymatic variable temperature and high throughput. The technology disclosed by the present invention can improve the utilization rate of the enzyme, and obtain the glucose-based stevioside with excellent sweetness and good taste.
C12P 19/56 - Préparation d'O-glucosides, p. ex. glucosides avec un atome d'oxygène du radical saccharide lié directement à un système cyclique condensé d'au moins trois carbocycles, p. ex. daunomycine, adriamycine
C12P 19/18 - Préparation de composés contenant des radicaux saccharide préparés par action d'une transférase glycosylique, p. ex. alpha-, bêta- ou gamma-cyclodextrines
brevets
