43results about How to "Achieve high density fermentation" patented technology

The invention provides a feeding lactic acid bacteria fermentation culture medium. The formula comprises 37-43 g / L of glucose, 47-55 g / L of a corn steep liquor dried powder, 42-48 g / L of fish meal, 0-2 g / L of K2HPO4.3H2O, 8-12 g / L of sodium acetate, 2-4 g / L of triammonium citrate, 0-0.5 g / L of MgSO4.7H2O, 0.25-0.5 g / L of MnSO4.H2O and 1-2 ml / L of Twain-80, wherein the pH value is 7.0-7.2, and water is used for preparation. The invention also provides a preparation method and an application of the fermentation culture medium. The cheap and easily available corn steep liquor dried powder and the fish meal are adopted to replace a nitrogen source ingredient in an MRS culture medium, the culture medium components are optimized, and the price of the obtained culture medium is only 40% of that of the MRS culture medium; through optimization of the fermentation initial pH value and the fermentation temperature, and simultaneously through adopting of a way of flowing addition of an NaOH solution to relieve feedback inhibition of lactic acid, the bacteria density is significantly improved compared with that of normal fermentation, the number of viable bacteria in a fermentation liquid is up to 10<10> CFU / ml or more, high density fermentation of feeding lactic acid bacteria is realized, and the specific production rate and the product quality are improved.

The invention relates to a high-density enterococcus faecalis fermentation culture medium and a fermentation process thereof. The fermentation culture medium is prepared from 20-30 g / L of glycerol, 10-15 g / L of soybean meal, 1-3 g / L of ammonium sulfate, 2-3 g / L of potassium hydrogen phosphate, 3-8 g / L of sodium acetate trihydrate, 2-4 g / L of trisodium citrate dihydrate, 0.3-0.8g / L of magnesium sulfate heptahydrate and 0.1-0.3 g / L of manganese sulfate monohydrate. The fermentation process comprises the steps that high dissolved oxygen (25%) is adopted and combined with glycerin to serve as a fermentation carbon source, the pH value of the constant sodium carbonate fermentation liquid is 5.5, the glycerol concentration is controlled to 10 g / L by adding a supplementary material in the fermentation process in a flowing mode, culture is performed for 16 hours, and then the fermentation is completed when OD (600 nm) is greater than 35, wherein the viable count of the enterococcus faecalis contained in the fermentation liquid can be up to 8*1010 CFU / mL or above. In the fermentation mode that the high dissolved oxygen is combined with the glycerin to serve as the carbon source, the lactic acid concentration in the fermentation liquid is reduced, the enterococcus faecalis contained in the fermentation liquid can be up to 8*1010 CFU / mL or above, the biomass separation cost is reduced, a production cycle is shortened, the production cost is reduced, and the production efficiency is improved.

The invention discloses a method for producing keratinase, which belongs to the technical field of microorganisms and fermentation. The present invention proceeds from two aspects of fermentation medium components (carbon source, nitrogen source, metal ion, phosphate) and fermentation conditions (temperature, pH, inoculum size), and utilizes Bacillus subtilis to ferment and produce the technique of keratinase. optimization. Utilizing the method of the invention to ferment and produce keratinase can increase the yield of keratinase by 3.3 times compared with the control, and the enzyme is produced in a 3L fermenter, and the enzyme activity reaches 704400U / mL. Therefore, the method of the present invention has broad application prospects in the preparation of keratinase in feed, tanning and the like.

The invention discloses a method and an apparatus for supplying and recycling oxygen in a process of high-density fermentation of aerobic microorganism. In the aerobic microorganism fermentation process, air is used as a gas source to prepare oxygen with the high density of 50 and 90 percent through a first oxygen generator I (1), and the oxygen with the high density of 50 and 99 percent is stored in a gas storage tank (2), and continuously aerated into an aerobic microorganism fermentation tank (3) by a regulated flow rate, and the first oxygen generator I(1) continuously uses the air as thegas source to prepare the oxygen with the high density; and the gas exhausted from an outlet of a fermentation tank (3) is led into a second oxygen generator II (4) to recycle the oxygen from the second oxygen generator II, and the gas is mixed with the oxygen with the high density prepared by the first oxygen generator I (1), and the gas is again led into the fermentation tank (3) to be circularly used in the fermentation process. The method and the apparatus can improve the production ratio of the aerobic fermentation process and reduce the production cost.

The invention discloses a Pseudomonas mendoza, which was preserved in the Guangdong Microbial Culture Collection Center on December 8, 2017, and the biological preservation number is GDMCC 60297. Correspondingly, the present invention also discloses the culture medium of Pseudomonas mendoza, including seed culture medium, fermentation medium and / or feed medium, wherein, fermentation medium comprises: starch 15-30g / L, corn steep liquor Dry powder 6-14g / L, dipotassium hydrogen phosphate 4-8g / L, ammonium sulfate 2-5g / L, magnesium sulfate heptahydrate 0.1-0.4g / L. Correspondingly, the invention also discloses a fermentation method of Pseudomonas mendoza and the application of Pseudomonas mendoza in sewage treatment. By adopting the invention, the low-cost and high-density fermentation of Pseudomonas mendoza is realized.

The invention belongs to the field of microbial fermentation, and more particularly relates to a method for preparing glutathione by fed-batch fermentation of Candida utilis. The method comprises: taking the Candida utilis SZU 07-01 as original strain, carrying out slant cultivation and seed cultivation on the original strain, and fermenting for at least 42 hour; and fermentation more particularly comprises the steps of: after expansion of cultivation, inoculating seeds into a fermentation medium according to 5-10% of inoculation quantity, and controlling the fermentation temperature within the range of 28-32 DEG C, the stirring rotation speed within the range of 250-300rpm and the ventilation capacity within the range of 0.5-1.5vvm; furthermore, when the fermentation is carried out for 10-12h, feeding the fermentation medium in batch; and manually adjusting the rotation speed and the ventilation capacity, and controlling the concentration of dissolved oxygen to be more than or equal to 35%. By adopting multinomial fed-batch fermentation way, on the basis of meeting the demand for nutrient substance of yeast cells, the method further improves the cell density and GSH yield, obviously reduces the fermentation time and increases the production efficiency.

The invention discloses a high-density fermentation process for recombinant nitrile hydratase Escherichia coli genetically engineered bacteria. Fed-batch fermentation is adopted in the process, and the procedures comprise: a cell rapid propagation stage, inoculating culture into a basal fermentation medium, wherein the temperature is 30-37 DEG C, the dissolved oxygen is 5-75%, the pH value is 6.8-7.2, and a specific growth rate of the engineering bacteria is 0.2-0.5; and an enzyme production stage: adding lactose induced engineering bacteria to produce enzymes until fermentation is ended whenthe cell concentration OD600 reaches 70-90, wherein the culture temperature is 15-25 DEG C, the dissolved oxygen is 5-75%, the pH value is 6.8-7.2, and the specific growth rate of the engineering bacteria is 0.01-0.1. According to the process disclosed by the invention, the fed-batch fermentation is manually divided into two stages, and culture conditions at each stage are controlled, so that high-density fermentation of the recombinant nitrile hydratase Escherichia coli genetically engineered bacteria is realized. The bacteria concentration of the engineering bacteria of producing nitrile hydratase is improved, and the enzyme activity of the nitrile hydratase is improved.

The invention provides a preparation method of gibberellic acid, comprising: S1) preparing gibberellic acid seed liquid; S2) transferring the gibberellic acid seed liquid into a fermenter for fermentation to obtain gibberellic acid fermentation liquid; S3 ) concentrating the gibberellic acid fermentation broth through membrane filtration to obtain a concentrated solution; S4) refining the concentrated solution to obtain gibberellic acid. Compared with the prior art, the present invention uses sugar and oil mixed supplementation in the fermentation process to increase the amount of acid production. At the same time, corn gluten powder is used as an organic nitrogen source, and its protein content is higher, reaching more than 50%. High-density fermentation can avoid the hidden dangers of Aspergillus flavus in peanut cake powder, ensure the synthesis and metabolism of bacteria, and enable rapid and stable fermentation; moreover, adding vegetable oil can not only provide carbon sources for fermentation, but also effectively Reduce the occurrence of fermentation bubbles escaping, and avoid potential risks such as material loss and bacterial contamination.

The invention provides a method for secretory expression of super-folded green fluorescent protein mediated heterologous protein in escherichia coli. The method includes steps: 1) constructing a secretory expression carrier pET23a / sfGFP-GFP taking sfGFP (super-folded green fluorescent protein) as a secretory tag; 2) constructing a heterologous protein gene recombinant expression carrier; 3) respectively converting and fusing the expression carriers to escherichia coli competent cell Rosetta Blue to obtain a recombinant strain; 4) expressing, culturing and performing functional verification; 5) performing high-density fermentation of the recombinant strain. According to secretion characteristics of the super-folded green fluorescent protein, extracellular secretory expression of the heterologous protein in escherichia coli in a fusion protein form is realized without mediating through signal peptides, an operation process is simplified, high autocrine performance is realized, functional influences of tag protein on target protein are avoided, expression conditions can be quickly optimized, target protein yield is increased, and the method is suitable for large-scale production. In addition, an application field of sfGFP is expanded, and a novel method is provided for extracellular secretory expression of the heterologous protein in escherichia coli.