403 results about "Staphylococcus lactis" patented technology

The invention provides a composite active bacterial preparation which is used for aquatic products and has the water improving and fertilizing functions and a preparation method thereof by applying a modern bioengineering technology mainly for the problem that in existing aquaculture, the water quality of a pond is poor. The composite microecological preparation is prepared by mixing bacillus subtilis, bacillus megatherium, bacillus amyloliquefaciens, bacillus licheniformis, enterococcus faecium, lactobacillus brevis, lactobacillus plantarum, lactococcus lactis and saccharomyces cerevisiae through liquid-submerged fermentation. In the liquid preparation, microorganisms are in a dormant state and are stable and easy to preserve, after the preparation is put into water, the dormant strains can quickly resuscitate, harmful substances such as nitrite nitrogen and ammonia nitrogen in the water are quickly decomposed, good algae growth is facilitated, harmful algae reproduction is inhibited, and therefore the purpose of improving the water quality of the culture water is achieved.

The invention relates to a cream cheese and a preparation method thereof. The technical scheme is to use milk fat raw material: 15-85%; whole milk: 10-80%; milk protein raw material: 1-10%; carbohydrate raw material: 1-10%. The present invention expands the raw material source of the cream cheese, uses milk protein raw material, carbohydrate raw material and stabilizer as ingredients, forms a stable texture without whey precipitation, and omits the process step of removing whey. The invention uses lactic acid bacteria including diacetyl lactis streptococcus to mix and ferment the ingredients of cream cheese, so that the product can form a new flavor.

The invention provides a preparation method of probiotics fermented pumpkin and carrot vegetable powder. The four probiotics, Lactobacillus rhamnosus, lactobacillus paracasei subsp. paracasei, streptococcus thermophilus, and lactococcus lactis subsp. Cremoris are adopted as the starting strains, which are then subjected to enlargement culture, preparation of lyophilized powder strains, compounding of lyophilized powder, thus obtaining composite probiotic lyophilized powder. The preparation method comprises the steps of: employing cleaned and seed removed pumpkins and cleaned carrots in a weight ratio of 3:1, adding drinking water of the same weight to the mixed material into a colloid mill for slurry refining, matching the slurry with 5% white sugar, after disinfection and cooling, inoculating the composite probiotic lyophilized powder with 0.01% of the slurry, carrying out fermentation for 48h, and then conducting centrifugal dehydration, wall material embedding with sodium alginate and a flaxseed gum, as well as freeze drying, thus obtaining the probiotics fermented pumpkin and carrot vegetable powder.

The invention relates to multifunctional compound microecological preparation nano-selenium-recombination expression VIP (vasoactive intestinal peptide)-lactococcus lactis and a preparation method. Toxic sodium selenite can be converted into non-toxic red simple-substance nano-selenium, and synthesized nano-selenium is enriched in lactococcus lactis NZ9000 in cells. The invention also discloses amethod for preparing a multifunctional compound microecological preparation SENPs-rVIP-L.lactis NZ9000 based on lactococcus lactis NZ9000. The problems that existing selenium supplementing additives have high toxicity action and low bioavailability and easily cause environment pollution, existing production technical procedures are complicated, the cycle is long and the production cost is high andthe problems about remaining of antibiotics, drug resistance and the like are solved.

The invention discloses a lactococcus lactis sub-specie lactis strain KLDS4001 having microorganism collection number of CGMCC No. 9964. The strain is strong in lactic acid-producing capability and good in fermentation performance and can be compounded with lactococcus lactis sub-specie cremoris to be applied as a cheddar leavening agent. The invention also discloses an application of the lactococcus lactis sub-specie lactis strain KLDS4001 in preparation of cheddar and a method for preparing cheddar by virtue of the strain. The method comprises the following steps of adding a compound leavening agent, which is prepared by mixing the lactococcus lactis sub-specie lactis strain KLDS4001 and the lactococcus lactis sub-specie cremoris, into raw milk and fermenting. The cheddar prepared by the compound leavening agent has the advantages of good maturity, texture and flavor and has a certain commercial value; and the physical and chemical indicators and microbial indicators of cheddar are in line with national standards.

The invention discloses lactobacillus capable of producing a sour taste. The lactobacillus is Lactobacillus casei YQ336, which is collected in China General Microbiological Culture Collection Center on July 15, 2016, with the collection number of CGMCC No. 12796. A sour-slurry coagulant is prepared by using the screened Lactobacillus casei YQ336 and commercially available lactococcus lactis, and is applied to the production of the sour-slurry tofu. The sour-slurry coagulant is high in fermenting speed and free of pollution caused by infectious bacteria and other pathogenic bacteria, so that the production speed is increased and the eating safety of the tofu is ensured; sour-slurry fermented liquid is used as the tofu coagulant, so that the eating safety of a tofu product can be adequately guaranteed; the sensory quality of the tofu produced in the invention is significantly superior to that of tofu produced by a naturally-fermented sour-slurry tofu coagulant.

The invention discloses a preparation method of cheese. The preparation method comprises the steps: (1), mixing malt extract and milk protein powder to obtain dry powder mixture; (2), raising the temperature of cow milk to 40 to 50 DEG C, stirring, mixing with the dry powder mixture to obtain pulp stock, and then hydrating the pulp stock after stirring and cooling; (3) raising the temperature of the pulp stock obtained in the step (2) to 50 to 65 DEG C, homogenizing, sterilizing, and cooling the temperature of the pulp stock to 27 to 37 DEG C; (4), mixing the pulp stock in the step (3) with a leavening agent and leavening, and the leavening agent is lactococcus lactis subsp lactis and lactococcus lactis cremoris; (5), cooling the temperature of the pulp stock in the step (4) to 20 to 25 DEG C and performing any one of the following operations: operation I, damaging curd and homogenizing; and operation II, damaging the curd, placing the curd into a die or a cloth bag to discharge whey, and the amount of the discharged whey is smaller than or equals to 50% but not is zero. The cheese prepared by the method has unique aroma, good taste, simple preparation process and various processing methods, can be suitable for different production lines, and needs short time for preparation.

The invention relates to a method for preparing cholesterol reducing eggnog fermenting drink by utilizing lactobacillus and microzyme which produce bile salt hydrolase, belonging to a functional drinkwhich is prepared from the following ingredients: 15% of whole egg pulp, 35% of milk, 7% of saccharose, 0.3% of CMC-Na. and 0.2% of carrageenin, wherein the ratio of the raw materials (the whole eggplug and the milk) to water is 1:1 (W/V). The primary fermentation condition is described as following: streptococcus thermophilus Tx, Lactococcus lactis subsp.lactis KS4 and Lactobacillus casei KL1 are mixed in proportion of 1:1:1, the inoculum size is 3%, and then the mixture is fermented for 8h at the temperature of 43 DEG C. The secondary fermentation condition is described as following: Kluyveromyces marxianus M3 and K1 are compounded in proportion of 1:1 or the inoculum size of the single strain is 1%, and then the composite is fermented for 24-26 h at the temperature of 30 DEG C (mixture strain) or 32-34 DEG C; after ripening is carried out for 1 day at the temperature of 4 DEG C, the reducing rate of raw material cholesterol reaches as high as 89.3%. By utilizing the characteristics of strain high-yielding BSH, exopolysaccharide and the like, the invention has the efficiencies of immunological regulation, cholesterol reducing, tumor prevention and the like, and the problem of egg smell is not only solved, but also the content of raw material cholesterol is efficiently reduced through egg pulp proper sterilization and eggnog secondary fermentation. The eggnog drink preparedby the invention has simple fermentation process, short period and lower cost and is suitable for industrialized production.

The invention provides fermented milk without food additives and a preparation method thereof. The fermented milk without the food additives comprises 86%-93.7% of raw milk, 0.2%-1% of milk protein powder, 0.1%-5% of single cream, 6%-8% of sugar and a fermentation strain of 4* 106-1.5*108 cfu/g. The fermentation strain comprises lactobacillus bulgaricus, streptococcus thermophilus and lactococcus lactis. The preparation method comprises the steps that 1, the milk protein powder, the sugar and the single cream are added to the preheated raw milk to be stirred; 2, homogenizing, sterilizing and cooling are conducted; 3, the fermentation strain is added, and fermentation is conducted for 3-5 hours at the temperature of 25-35 DEG C; 4, fermentation is conducted at the temperature of 37-45 DEG C until the degree of acidity reaches 70-80 oT; 5, cooling and instant cold storage are conducted, and then post-maturation is conducted for 12-24 hours. By the adoption of the preparation method of the fermented milk without the food additives, the fermented milk has strong milk flavor, and the possibility of the bleeding phenomenon during the shelf life is reduced.

The invention discloses a preparation method of a composite microbial starter culture and application thereof. The method is characterized by comprising the following steps: separating out lactobacillus plantarum, lactobacillus sake, lactococcus lactis and leuconostoc mesenteroides from a fermentation liquor of natural fermentation sauerkraut, producing strains by taking dabaryomyces hansenii as a leavening agent; independently producing the leavening agent, so that the viable count is greater than or equal to 10<9> per ml, and then respectively preparing freeze drying powder from different strains; evenly mixing according to the mass ratio of the lactobacillus plantarum to the lactobacillus sake to the lactococcus lactis to the leuconostoc mesenteroides to the dabaryomyces hansenii being (2-3):(2-3):(1-2):(1-2):(1-2), so as to prepare the composite microbial starter culture. The composite microbial starter culture is applied to a fermented vegetable product, so that growth of infectious microbes and harmful bacteria can be avoided, the quality of the fermented vegetable product can be improved, meanwhile, compared with a single strain starter culture, more flavor substances can be generated by adopting the composite microbial starter culture of the saccharomycetes and the lactic acid bacteria, the flavor is closer to the traditional natural fermented vegetable products, and production controllability and modern production are achieved.

The invention discloses an acid-stress-resisting component and belongs to the technical field of biological engineering. An rbsA gene obtained from lactococcus lactis (L.lactis NZ9000) is excessivelyexpressed in the lactococcus lactis (L.lactis NZ9000) to obtain recombinant lactococcus lactis (L.lactis NZ9000) (pNZ8148/RbsA) with the remarkably improved acid-stress-resisting capability. The survival rate of a recombinant strain is 5.8 times as much as that of a control group after the recombinant strain is stressed for 3h under the condition that the pH (Potential of Hydrogen) is 4.0. The invention further provides a method for improving the acid stress resistance; the method has good industrial application value.

The invention relates to fertilizer pesticide, and specifically relates to an organic fertilizer fermenting agent and a preparation method thereof. The fermenting agent is composed of bacillus subtilis, bacillus mucilaginosus, trichoderma viride, lactococcus lactis, actinomycetes, azotobacter chroococcum, bacillus megatherium, bacillus mucilaginosus, escherichia coli, active ingredient, cellulose, protease and phosphorylase. The preparation method of the fermenting agent comprises the following steps: 1, weighing each constituent; 2, preparing a mixture I; 3, preparing a mixture II; 4, smashing. According to the invention, active ingredient is added into the fermenting agent, so that effective viable count content in the fermenting agent is improved greatly, heating and fermenting time is reduced, and absorption and utilization rates of the fermenting agent by poultry dung, straw, and the like, are improved. Aspergillus niger in the active ingredient is uniformly stirred with other constituents after being stirred well with orangeade, thus, absorption and utilization of the organics in the active ingredient by various microbes in the fermenting agent are promoted greatly, and the increase of effective viable count in the fermenting agent is facilitated.

The invention discloses a preparation method of additive-free milk, comprising the following steps: (1) carrying out falling-film condensation on raw milk, or carrying out falling-film condensation on partial raw milk and mixing condensation products with rest raw milk; (2) homogenizing, sterilizing and cooling substances obtained in step (1); and (3) fermenting substances obtained in step (2) with lactobacillus bulgaricus and lactococcus lactis and carrying out cooling. The invention also discloses additive-free fermented milk prepared by the method. The additive-free milk provided in the invention is good in both quality and flavor, and is helpful for satisfying consumers' health need for additive-free food. By decreasing consumers' intake of food additives, the additive-free milk is helpful for reducing body burdens and enhancing human immunity.

The invention discloses a method for performing fermentation production on gamma-aminobutyric acid by using high-concentration monopotassium phosphate as a buffer salt, and belongs to the field of microbe fermentation engineering. The method comprises the following steps: using lactococcus lactis (Lactococcus lactis SYFS1.009) which can produce gamma-aminobutyric acid as a strain, culturing the lactococcus lactis in a culture medium containing high-concentration monopotassium phosphate, wherein the culture medium comprises the following components: 10-40 g/L of glucose, 20-50 g/L of yeast extract, 20-50 g/L of monopotassium phosphate, 5-20 g/L of sodium glutamate, 0-3 g/L of MgSO4, 0-3 g/L of MgSO4.H2O and 0-5mL/L of Tween-80; performing fed-batch operation on ammonia water or sodium hydroxide to regulate the pH of the fermentation liquor on the basis of the culture medium, adding a certain amount of glucose and sodium glutamate in the fermentation process, and culturing for 40-60 hours to obtain the fermentation liquor containing high-concentration gamma-aminobutyric acid. The used culture medium and method are safe, reliable and short in production cycle, the pH of the fermentation liquor is regulated by using the monopotassium phosphate as the buffer salt and performing fed-batch operation on the ammonia water or sodium hydroxide, and an inhibiting effect of lactic acid on the lactococcus lactis can be effectively relieved.

The invention discloses an anti-acid-stress component and application thereof, belonging to the field of bioengineering technology. According to the invention, two recombinant Lactococcus lactis strains with substantially improved resistance to acid stress, i.e., L. lactis NZ9000 (pNZ8148/RecT-A76) and L. lactis NZ9000 (pNZ8148/RecT-MG1655), are obtained by overexpression of recT genes, originated from Lactococcus lactis L. lactis A76 and Escherichia coli E. coli MG1655, in Lactococcus lactis NZ9000, respectively. After the two recombinant Lactococcus lactis strains suffer from stress in an environment with a pH value of 4.0 for 3h, the survival rates of the two strains are 10.5 times and 1.4 times the survival rates of control strains, respectively; and after the two strains suffer from stress caused by 20% (v/v) ethanol for 6 h, the survival rates of the two strains are 3.7 times and 2.1 times the survival rates of control strains, respectively. The invention also provides a method for improving resistance to acid stress. The method has good industrial application value.

The invention belongs to the field of animal biomedicine engineering, and in particular discloses protein recombinant lactococcus lactis for secretory expression of a core antigen COE of a PEDV (Porcine Epidemic Diarrhea Virus) as well as a preparation method and an application of the protein recombinant lactococcus lactis. The method comprises the following steps: connecting a signal peptide and other sequences onto a gene of the core antigen COE of the PEDV via an overlap extension PCR method by designing multiple primers, connecting the gene to a lactococcus lactis expression vector pNZ8048 and introducing the vector with the gene into a cell of the lactococcus lactis NZ9000 in an electrotransformation manner so as to obtain recombinant bacteria; and inducing the recombinant bacteria with nisin so as to obtain an expression, and directly taking all induced cultures as oral vaccines capable of stimulating mice and inducing strong cellular immune responses. Thus, the protein recombinant lactococcus lactis can serve as a novel oral vaccine product with a good industrial prospect and has a positive effect for reducing harms of the PEDV to pig industry, thereby playing a great practical significance for promoting the healthy development of the pig industry.

The invention discloses an efficient preparation method and applications of food-grade acid ureases, belonging to the technical field of biological engineering. The efficient expression and preparation methods and applications of acid ureases are realized successfully by using food-grade lactococcus lactis expression system, the enzyme activity of the acid ureases reaches 10200 U/L, and the enzyme activity of purified acid ureases is 325.6 U/mg. The specific enzyme activity of purified enzymes to an urethane substrate reaches 243.4 U/mg, and food-grade acid ureases which are prepared by using the method disclosed by the invention and added in a yellow rice or millet wine can efficiently degrade urea (the degradation rate per two days is 100%) and urethane (the degradation rate per three days is 72% %). Recombined acid ureases prepared by using the method disclosed by the invention can be applied to the removal of urea and urethane in fermented food, so that the residue problem of urethane in fermented food can be efficiently solved. The efficient preparation method and applications of food-grade acid ureases disclosed by the invention lay a foundation for the implementation of the industrialized production of food-grade acid ureases.

The invention provides an extraction method of bile salt hydrolase (BSH) and extracellular polysaccharide (EPS) in lactococcus lactis and streptococcus thermophilus, and the BSH and the EPS acting as functional factors and the EPS as a natural stabilizer in a functional dairy product are applicable for developing and producing novel functional food. The method utilizes lactococcus lactis subsp. lactis KS4 (CGMCC No.1807) and streptococcus thermophilus Tx (CGMCC No.1810) of the high-yield BSH and EPS, and obtains lactobacillus bile salt hydrolase and extracellular polysaccharide crude products through optimizing fermentation conditions and the extraction method. The adoption of the optimum ultrasonic cell disruption extraction method can solve the problem of difficult extraction of intracellular bile salt hydrolase; and the extraction rate of EPS is increased by optimizing the extraction conditions of EPS. The fermentation technique and the extraction method for preparing the BSH and EPS are simple, the fermentation period is rather short, and the method has low requirements on equipment and cost, and is applied to the industrialized production.

The invention relates to a carrier capable of showing and expressing a heterologous gene on the surface of lactococcus lactis, and a preparation method and application of the carrier. The carrier has the nucleotide sequence which is shown as SEQ ID NO.1 in a sequence table, and contains promoter Pnis and lysM genes, a signal peptide secretion sequence ssusp45, a multiple cloning endonuclease site, and replicon repA and repC components. A method for constructing the carrier has the following steps of: amplifying a lactococcus lactis NZ3900 strain autolysin (AcmA) anchoring area gene lysM by applying a polymerase chain reaction (PCR) technology, performing enzyme digestion on the lysM and a carrier pNZ8110 and connecting, wherein a connection product is used for transforming a E.coli MC1061 strain, and extracting recombinant plasmid from positive transformed bacteria which are subjected to enzyme digestion and sequencing identification to obtain the expression carrier. The exogenous gene and the carrier are connected and then transferred into lactococcus lactis NZ3900, and the expression of the exogenous gene and the combination of expression protein and host cell walls can be realized by induction of nisin. The carrier can be used for expressing foreign proteins including vaccine antigens and has a wide application range.

The invention discloses a compound microbial agent for anaerobic digestion treatment of sludge and a production method of the compound microbial agent. The compound microbial agent is a liquid microbial agent which is prepared through fermentation culture and comprises the following bacteria: bacillus subtilis, streptomyces albus, streptomyces griseus, candida utilis, aspergillus sojae, lactobacillus bulgaricus, lactococcus lactis, rhodopseudomonas palustris, rhodopseudomonas capsulate and rhodobacter sphaeroides, and the number of total viable bacteria in 1ml of the compound microbial agent is not less than 2*10<8>. All the bacteria used by the compound microbial agent have metabiosis and symbiosis effects and form a biodegradation system with very high enzymatic activities. When the compound microbial agent disclosed by the invention is used for carrying out anaerobic digestion treatment on sludge, the degradation rate of organic matters can be effectively increased, the sludge hydrolytic process can be accelerated, the anaerobic digestion time of the sludge can be shortened, and the biological gas yield can be increased.

The invention provides for anti-pathogen vaccines produced in recombinant bacteria and/or transgenic plants and administered through standard vaccine introduction methods or oral administration. In one embodiment, the vaccine is administered through the consumption of the edible plant as food, or the bacteria administered orally. The present invention also provides a method of using genetically modified microorganisms, such as lactic acid bacteria, including Lactococcus lactis strains, as oral vaccines. In one embodiment, Lactococcus lactis expressing the avian influenza HA gene can be used as an oral vaccine for protection against H5N1 virus infection. In another embodiment, said Lactococcus lactis is administered as an oral vaccine in conjunction with an adjuvant such as cholera toxin B.

The present invention discloses a preparation method for a bio-organic fertilizer using a novel fermentation agent. The novel fermentation agent added in the bio-organic fertilizer is composed of industrial fermentation offscum, bacillus subtilis, silicate bacteria, trichoderma viride, lactococcus lactis, actinomycete, azotobacter chroococcum, bacillus megaterium, bacillus mucilaginosus Krassilnikov, Escherichia coli, active materials, cellulase, protease, straw, lactobacillus plantarum, bacillus licheniformis and phosphorylase. The bio-organic fertilizer is prepared by using the novel fermentation agent following the preparation method. The novel fermentation agent greatly promotes a variety of microorganisms of the fermentation agent to absorb and utilize organic materials of the active materials, and helps to improve effective numbers of viable organisms of the fermentation agent and increase nutrients greatly.

The invention discloses a preparation method of a porcine epidemic diarrhea virus genetic engineering subunit oral vaccine. The method comprises the following steps of: 1) synthesizing an M gene; 2) constructing an expression vector; 3) performing protein induction expression; 4) carrying out recombinant strain preservation experiment; and 5) preparing the vaccine. The oral immunization has the advantage of effectively stimulating local immune cells of the intestinal tract to generate secretion type IgA, is especially applicable to the infectious disease of the intestinal mucosa, and avoids stress and vaccine absorption problems resulting from conventional vaccine injection; and as a safe and non-toxic live vector system capable of living on the intestinal mucosa, the lactococcus lactis is the most suitable vector system. The oral vaccine performs antigen presentation through the gastrointestinal mucosa, and produces immune reaction similar to conventional injection through different immune pathways.