摘要:
Provided are a sucrose synthetase and the use thereof. Compared with SEQ ID NO: 11, an amino acid sequence of the sucrose synthetase contains differences in amino acid residues selected from one or more of the following residue positions: an amino acid at position 36 being V, an amino acid at position 43 being E, an amino acid at position 179 being A, an amino acid at position 395 being R, an amino acid at position 447 being P, an amino acid at position 455 being L, and an amino acid at position 654 being R; and the sucrose synthetase has an activity not lower than that of a sucrose synthetase having an amino acid sequence as shown in SEQ ID NO: 11. By means of catalyzing the synthesis of rebaudioside A, rebaudioside D or rebaudioside M by using a glucosyltransferase and the sucrose synthetase in a combined manner, a cascade reaction is achieved, thereby providing a variety of possibilities for the selection of raw materials.
摘要:
The present invention relates to a recombinant microorganism comprising one or more nucleotide sequence(s) encoding: a polypeptide having ent-copalyl pyrophosphate synthase activity; a polypeptide having ent-Kaurene synthase activity; a polypeptide having ent-Kaurene oxidase activity; and a polypeptide having kaurenoic acid 13-hydroxylase activity, whereby expression of the nucleotide sequence(s) confer(s) on the microorganism the ability to produce at least steviol. The recombinant microorganism may also be capable of expressing one or more UDP-glucosyltransferases such that the microorganism is capable of producing one or more steviol glycosides.
摘要:
[Problem to be Solved] The present invention aims to provide steviol glycosyltransferase and a method for producing a steviol glycoside using this enzyme. [Means to Solve the Problem] The present invention provides steviol glycosyltransferase and a method for producing a steviol glycoside using this enzyme. The present invention provides a transformant transformed with a gene for steviol glycosyltransferase and a method for preparing such a transformant.
摘要:
Isolated mogroside and mogrol biosynthetic pathway enzyme polypeptides useful in mogroside biosynthesis are provided. Mogroside biosynthetic pathway enzymes of the invention include squalene epoxidase (SE), expoxy hydratase (EH), cytochrome p450 (Cyp), cucurbitadienol synthase (CDS) and udp-glucosyl-transferase (UGT). Also provided are methods of producing a mogroside using the isolated mogroside and mogrol biosynthetic enzyme polypeptides, the methods comprising contacting a mogrol and/or a glycosylated mogrol (mogroside) with at least one UDP glucose glucosyl transferase (UGT) enzyme polypeptide of the invention catalyzing glucosylation of the mogrol and/or the glucosylated mogrol to produce a mogroside with an additional glucosyl moietie(s), thereby producing the mogroside. Alternatively or additionally provided is a method of synthesizing a mogrol, the method comprising contacting a mogrol precursor substrate with one or more mogrol biosynthetic pathway enzyme polypeptides as described herein catalyzing mogrol synthesis from the mogrol precursor substrate, thereby synthesizing the mogrol.
摘要:
A recombinant host capable of producing a steviol glycoside which overexpresses a polypeptide which mediates steviol glycoside transport and which polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 35 or SEQ ID NO: 38 or an amino acid sequence having at least about 50% sequence identity to either thereto. A recombinant host capable of producing a steviol glycoside which has been modified, preferably in its genome, to result in a deficiency in the production of a polypeptide which mediates steviol glycoside transport and which polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 35 or SEQ ID NO: 38 or an amino acid sequence having at least about 50% sequence identity to either thereto.
摘要:
Disclosed are methods for producing steviol glycosides, such as rebaudioside D and rebaudioside M, using engineered yeast. In some embodiments, the methods include fermenting with a yeast at a high pH such as of about 5.8 or greater. In some embodiments, the methods can be carried out by first growing the yeast at a lower first pH, and then adjusting the pH to a higher pH.
摘要:
Methods of preparing highly purified steviol glycosides, particularly rebaudiosides A, D and M are described. The methods include utilizing recombinant microorganisms for converting various staring compositions to target steviol glycosides. In addition, novel steviol glycosides reb D2 and reb M2 are disclosed, as are methods of preparing the same. The highly purified rebaudiosides are useful as non-caloric sweetener in edible and chewable compositions such as any beverages, confectioneries, bakery products, cookies, and chewing gums.
摘要:
a. contacting said composition comprising steviol glycosides with a recombinant microorganism, a cell free extract derived from such a microorganism or an enzyme preparation derived from either thereof; and b. thereby to increase the degree of glycosylation of the composition comprising steviol glycosides, wherein the recombinant microorganism comprises one or more nucleotide sequence(s) encoding: a polypeptide having ent-copalyl pyrophosphate synthase activity;a polypeptide having ent-Kaurene synthase activity; a polypeptide having ent-Kaurene oxidase activity; a polypeptide having kaurenoic acid 13-hydroxylase activity; and one or more polypeptides having UDP-glucosyltransferase activity whereby expression of the nucleotide sequence(s) confer(s) on the microorganism the ability to produce at least one steviol glycoside. The present invention also relates to a composition comprising steviol glycosides obtainable by such a method.
摘要:
Disclosed are steviol glycosides referred to as rebaudioside V and rebaudioside W. Also disclosed are methods for producing rebaudioside M (Reb M), rebausoside G (Reb G), rebaudioside KA (Reb KA), rebaudioside V (Reb V) and rebaudioside (Reb W).