71 results about "Kluyveromyces lactis" patented technology

The invention discloses a raw material composition of a fermented milk beverage. The raw material composition comprises the following raw materials in percentage by mass: 35-60% of a fermented milk base material, 0.05-1% of a stabilizing agent, 5-15% of a sweetening agent and the balance of water, wherein the fermented milk base material is prepared through fermentation of raw material milk and lactic acid bacteria, and the stabilizing agent comprises the following components of (a) one, or two or more of sodium carboxymethyl cellulose, propylene glycol alginate, pectin, agar, starch, carrageenin and gellan gum; and (b) one, or two or more of mono(di)glycerin fatty acid ester, acetylated mono(di)glycerin fatty acid ester, and diacetyl tartaric acid ester of mono(di)glycerides. The raw material composition of the fermented milk beverage provided by the technical scheme of the invention is used as a raw material, and kluyveromyces lactis (kluyveromyces lactis) is added for fermentation, so that a gas-containing fermented milk beverage is made. The fermented milk beverage is subjected to secondary fermentation of lactic acid bacteria and microzymes, contains gas produced by natural fermentation, and is high in irritating mouth feel, unique in flavor, and good in stability.

The invention belongs to the technical field of tobacco additives, and particularly relates to an upgrading and purifying method of a raisin extract and application of the raisin extract. One or more of biological agents of alpha-L-rhamnopyranoside enzyme, endo protease and kluyveromyces lactis powder are adopted to conduct hydrolysis and fermentation on raisin frozen pulverized objects, then through the combination of ethyl alcohol alcohol precipitation, reduced pressure distillation and ultrafiltration membrane separation technologies, the raisin extract which is upgraded and purified is obtained. The raisin extract is less in impurity, the content of bioactivity components is increased, the fragrance is richer, the aromatic quality is improved, and when the raisin extract is applied to a cigarette product, the raisin extract can be coordinated with smoke, has sweet aroma of grapes, the irritation is lowered, the adulteration gas is reduced, and the quality is improved.

The invention belongs to the technical field of gene engineering, in particular to a technical proposal used to improve the expression level of recombinant protein. In the method, a promoter, alpha-signal peptide, target protein of an inulase gene are orderly connected with a terminal subcode sequence of the inulase gene first; then the sequence is inserted into a Kluyveromyces lactis expression vector; finally the Kluyveromyces lactis is transformed and fermented, and a fermented supernatant is taken and separated. The method can accelerate the remarkable growth of the yield of the recombinant protein expressed in the Kluyveromyces lactis. The technical proposal can be used to improve the expression amount of various proteins and provide a new method for reducing production cost and enlarging production scale.

A process for producing cheese, cheese analogues and cheese-derived products comprises contacting said cheese, analogues or products with a Kluyveromyces lactis cell or an enzyme derived therefrom.

The invention discloses aldehyde ketoreductase bacterial strain, aldehyde ketoreductase gene, a vector, engineering bacteria and an application thereof. A nucleotide sequence of aldehyde ketoreductase gene is one of a SEQ ID No. 1, a SEQ ID No. 3 and a SEQ ID No. 5, aldehyde ketoreductase gene shown by the SEQ ID No. 1 and the SEQ ID No. 3 comes from bacterial strain-kluyveromyces lactis XP1461, and aldehyde ketoreductase gene shown by the SEQ ID No. 5 comes from bacterial strain-baeyer zygosaccharomyces bailii XP1462. The disclosed aldehyde ketoreductase from K.lactis and Z. bailii can be firstly reported for biological catalyzed synthesis of 6-cyan-(3R, 5R)-dihydroxyhexanoate, optical voidness of the prepared sample 6-cyan-(3R, 5R)-dihydroxyhexanoate can be reached, existence of 6-cyan-(3R, 5R)-dihydroxyhexanoate can be hardly detected; high epimerase selectivity of aldehyde ketoreductase brings benefit, and the products extraction yield is high.

The invention provides an in-vitro cell-free protein synthesis system and a kit and use thereof, and belongs to the technical field of protein synthesis. The in-vitro cell-free protein synthesis system based on a kluyveromyces lactis source is improved by adding exogenous L-arabinose, such that the protein synthesis capability of the system is remarkably improved. The invention further provides a more efficient and higher-throughput in-vitro protein synthesis kit and a synthesis method of a foreign protein. The provided improved method can be realized without molecular modification, is simple and convenient to operate and saves cost.

This invention relates to cloning and sequencing of thermotolerant phytase gene from Non-K12 Escherichia coli strain, ATCC 9637, phytase gene expression in Escherichia coli expression system, codon usage optimized and expression in Pichia pastoris, Pichia methanolica and Kluyeromyces lactis. The high level yield and thermotolerant enzyme was produced from fermentation of Pichia pastoris with optimized codon of phytase gene.

The invention relates to a method for preparing galactooligosaccharide by use of permeable cell beta-galactosidase, which comprises the following steps of: adding permeable cell beta-galactosidase into a lactose solution, wherein the concentration of the lactose solution is 100-500g/L, and the addition amount of permeable cell beta-galactosidase is 200-1,500mg per gram of lactose; reacting for 2-15 hours at 30-45 DEG C; and performing centrifugal separation, wherein the obtained supernate is a galactooligosaccharide solution. By preparing galactooligosaccharide by use of permeable cell beta-galactosidase, the extraction and purification processes of endoenzyme are avoided, the technological operation is simplified, and the production cost is reduced. Kluyveromyces lactis is processed by absolute ethyl alcohol to prepare a permeable cell, toxic chemical reagents such as chloroform and the like are not introduced, the food safety problem is avoided, and the permeable cell can be widely applied to the food industry. Moreover, the permeable cell can be used repeatedly, thus the production cost of galactooligosaccharide can be obviously reduced.

The invention discloses a method for fermenting Anfu ham by utilizing a compound micro-ecological fermenting agent and belongs to the field of food fermentation. The method for fermenting Anfu ham by utilizing the compound micro-ecological fermenting agent comprises the following steps: pre-treating, salting, dehydrating, firstly fermenting and secondly fermenting. The bacterial strains in the compound micro-ecological fermenting agent include lactobacillus pentosus, lactobacillus plantarum, kluyveromyces lactis and issatchenkia orientalis, wherein the number ratio of lactobacillus pentosus to lactobacillus plantarum to kluyveromyces lactis to issatchenkia orientalis is 1:(1-3): (1-3):(1-5) and the total amount of viable bacteria of the compound micro-ecological fermenting agent is 3*106-8*10<6>cfu/mL. According to the method for fermenting Anfu ham by utilizing the compound micro-ecological fermenting agent disclosed by the invention, the ham having characteristics of short production period, natural product color, high yield, various flavors and the like can be prepared in the manner of adding the compound micro-ecological fermenting agent and the compound seasoning into the ham meat.

The invention provides a Kluyveromyces marxianus derived high-expression promoter KmINU1 promoter, and an efficiently in vitro excreted signal peptide and an expression system thereof. The KmINU1 promoter having a nucleotide sequence represented by SEQ ID No.2 has strongest promotion activity, and has far higher activity than known KmPGK promoters. The KmINU1 promoter can start expression of a downstream gene without induction, and a target gene can efficiently express after stably growing in host cells, and is especially suitable for expression of exogenous genes influencing the growth of the host cells. The expression system containing the KmINU1 promoter and the efficiently in vitro excreted signal peptide, constructed in the invention, is suitable for various microzymes, such as Saccharomyces cerevisiae, Kluyveromyces lactis and Kluyveromyces marxianus, and lays a foundation for efficient expression of different exogenous genes.

The invention relates to a nucleic acid molecule encoding a novel selection marker. Said marker is a guanidinobutyrase from Kluyveromyces lactis, which, when expressed in Saccharomyces, allows the growth of the yeast in the presence of guanidinobutyrate as the sole nitrogen source. Said marker can be used in a method for producing a microorganism having an altered genome. The invention further relates to a set of constructs, comprising a first construct comprising a recognition site for an endonuclease, a first region of homology with a target gene of a microorganism, and a first part of a nucleotide sequence encoding the selection marker, and a second construct comprising a second part of the nucleotide sequence encoding the selection marker, a second region of homology with the target gene of the microorganism, and a copy of the endonuclease recognition site. The invention further relates to methods for altering a target gene in a microorganism, to methods for producing a microorganism, and to microorganisms that are produced by the methods of the invention.

Methods and compositions are provided relating to production of recombinant protein in yeast. A modified PLAC4 is described where one or more mutations may be introduced into the Pribnow box-like sequences in the promoter. The modified promoter when placed upstream of a target gene in a vector causes a significant reduction of target gene expression in transformed bacteria but produces efficient expression of the target gene in yeast.

The invention relates to construction of a free non-methanol induced pichia pastoris expression vector and an application of the expression vector in enzyme recombination expression, and belongs to the technical field of genetic engineering. The non-methanol induced pichia pastoris expression vector is obtained by inserting a kluyveromyces lactis autonomous replication sequence PARS2 and a pichiapastoris promoter PGCW14 sequence into a vector framework, and constructing a free vector with a self-replication sequence. Compared with the general integrated recombinant pichia pastoris engineeringbacteria, the free recombinant pichia pastoris engineering bacteria constructed by the vector have obviously-improved capability of secreting and producing recombinant enzymes. In addition, the fermentation raw materials have wide sources, and the production cost is low.

The invention provides a screening method of a D-arabitol high-yield yeast mutant strain. By using a mutant strain obtained by carrying out mutagenesis on Kluyveromyces lactis by a low-energy N+ ion implantation technique as a screening object, a high-flux screening method, which is implemented by primary screening based on a high-sugar solid culture medium and secondary screening based on paper chromatography/high-performance liquid chromatography combination, is established. The method has the advantages of high screening efficiency, low cost, short screening period and the like, is easy to operate, and provides a new method for efficiently screening the D-arabitol high-yield strain by modifying the yeast with low-energy ion implantation.

The invention provides a method for constructing a multi-copy kluyveromyces lactis expression vector efficiently in an in-vitro manner. The method comprises the following steps: 1) 10 primers for PCR are designed and synthesized according to the gene sequence of a carrier pKLAC2 of kluyveromyces lactis GG799; 2), synthesizing the gene segments of yeast expression nuclear structures of four restriction enzyme loci; 3) constructing the expression vector BpKLAC2; 4) using the restriction enzyme loci to verify the accuracy of the expression vector through digestion; 5) inserting a target gene in the expression vector BpKLAC2 to become the single-copy expression vector containing the target gene; and 6) applying the biological bricking method to achieve the in-vitro multi-copy of the expression vector. Through the application of the method, the expression quantity and the stability of the target protein gene of the kluyveromyces lactis can be improved.

The invention relates to a microbial fertilizer capable of reducing the amount and increasing the efficiency of a chemical fertilizer as well as a preparation method and application of the microbial fertilizer. The microbial fertilizer capable of reducing the amount and increasing the efficiency of a chemical fertilizer comprises biochar, a compound fermentation inoculant, a compound functional inoculant and an organic material; the compound fermentation inoculant comprises bacillus subtilis powder, streptococcus thermophilus powder and kluyveromyces lactis powder; and the compound functional bacterial agent is prepared from paenibacillus mucilaginosus powder, rhodopseudomonas acidophila powder and bacillus methylotrophicus powder. The microbial fertilizer is stable in fertilizer efficiency, can reduce the application amount of a chemical fertilizer, can promote plant growth, reduce the prevalence rate and death rate of plants, improve the crop yield and increase economic income, and has important application value in vegetable planting.

The invention relates to a method for preparing high-purity galactooligosaccharide by beta-galactosidase. The method comprises the following steps: (1) preparing galactooligosaccharide (GOS) by usingfree beta-galactosidase to catalyze lactose through a transglycosylation reaction; (2) performing whole-cell fermenting preparation with Kluyveromyces lactis; and (3) obtaining the high-purity galactooligosaccharide by whole-cell purification with the Kluyveromyces lactis. After a GOS synthesis is carried out for 2 hours, the GOS yield is 22.78%, and after whole-cell treatment with Kluyveromyces lactis is carried out for 15 hours, the purity of GOS is over 90%. The process provides a simple, efficient and inexpensive method for production of high-purity oligosaccharides. The GOS produced by the method is high in purity, low in production process cost and high in efficiency, is green and environmentally friendly, and is expected to be widely applied.