阅读说明：本技术 黄原胶的生产和分离工艺 (Process for producing and separating xanthan gum ) 是由 薄文文 郑世涛 刘建阳 来凤堂 李树标 范婷婷 王婷 于 2020-06-28 设计创作，主要内容包括：本发明属于发酵生产技术领域,公开了黄原胶的生产和分离工艺,其包括恒容发酵工序和分离提取工序。本发明生产工艺简单、操作方便、提取成本低,产品透光率高。(The invention belongs to the technical field of fermentation production, and discloses a production and separation process of xanthan gum, which comprises a constant volume fermentation process and a separation and extraction process. The invention has simple production process, convenient operation, low extraction cost and high product light transmittance.)

1. The production and separation process of xanthan gum includes constant volume fermentation process and separation and extraction process.

2. The process according to claim 1, wherein the constant volume fermentation process comprises the steps of:

step 1) inoculating the xanthomonas seed solution into a 300L fermentation tank filled with 200L fermentation medium for fermentation culture for 48 h;

step 2) feeding nutrient solution from the upper part of the fermentation tank at the speed of 0.2L/min, and discharging the fermentation liquor from a discharge hole at the lower part of the fermentation tank at the speed of 0.2L/min;

step 3), when the fermentation is carried out for 80 hours, the concentration of xanthan gum in the tank begins to be in a descending trend, and when the fermentation is carried out for 84 hours, the fermentation is finished; and (3) combining the fermentation liquor in the step 2) and the fermentation liquor in the fermentation tank for the subsequent separation and extraction process.

3. The process according to claim 2, wherein the constant volume fermentation process comprises the steps of:

step 1) inoculating the Xanthomonas seed solution into a 300L fermentation tank filled with 200L fermentation medium according to the inoculation amount of 10% for fermentation culture, wherein the inoculation concentration OD₆₀₀1.5-2.0, fermenting at 30 deg.C, controlling dissolved oxygen at 20%, and fermenting for 48 hr;

step 2) then feeding nutrient solution from the upper part of the fermentation tank at the speed of 0.2L/min, and simultaneously discharging the fermentation liquor from a discharge hole at the lower part of the fermentation tank at the speed of 0.2L/min;

step 3), maintaining the concentration of xanthan gum in the fermentation tank at a constant concentration, starting to be in a descending trend when the fermentation is carried out for 80 hours, and stopping the fermentation tank to finish the fermentation when the concentration of the xanthan gum in the fermentation tank is reduced to 15 g/L when the fermentation is carried out for 84 hours; and (3) combining the fermentation liquor in the step 2) and the fermentation liquor in the fermentation tank for the subsequent separation and extraction process.

4. The process of claim 2, wherein the components of the nutrient solution comprise: glucose, ammonium chloride, ethanol, arginine, methionine, VB₁。

5. The process of claim 2, wherein the fermentation medium comprises the following components: 40g/L glucose, 60g/L corn starch, 5g/L yeast powder, 10g/L oleic acid, 3g/L calcium carbonate, 1g/L magnesium sulfate heptahydrate, 1g/L dipotassium phosphate and 20mg/L, VB fulvic acid₁20mg/L，pH 7.0-7.2。

6. The process according to claim 4, wherein the nutrient solution comprises the following components: 50g/L glucose, 10g/L ammonium chloride, 10g/L ethanol, 2g/L arginine, 2g/L methionine and VB₁10mg/L。

7. The process according to claims 2-4, wherein the separation and extraction process comprises the following steps:

centrifuging the fermentation liquor by a high-speed disc centrifuge, collecting the upper-layer liquid, and performing centrifugation according to the volume ratio of 100L: adding a perlite filter aid into 1kg of the mixture, filtering, adjusting the pH value of the filtrate to 5.0, adding ethanol into the solution, controlling the volume percentage concentration of the ethanol in the solution to be 55%, stirring for 45min, naturally settling for 15min, centrifuging at 500rpm for 3min, and collecting precipitates; adding ethanol into the precipitate, controlling the volume percentage concentration of the ethanol in the solution at 60%, stirring for 40min, naturally settling for 15min, centrifuging at 500rpm for 3min, collecting the precipitate, and finally drying and crushing to obtain the xanthan gum product.

8. The process of claim 7, wherein the high speed disc centrifuge has a centrifuge speed of 5000rpm and a centrifuge time of 4 min.

Technical Field

The invention belongs to the technical field of fermentation production, and particularly relates to a production and separation process of xanthan gum.

Background

Xanthan gum is a microbial polysaccharide which is produced by taking carbohydrate as a raw material of Xanthomonas campestris through fermentation and has wide application, can be dissolved in cold water and hot water, forms a high-viscosity solution after being fully hydrated, has efficient thickening effect, and has good temperature resistance, salt resistance, heat resistance and acid and alkali resistance. The xanthan gum has good water solubility, forms a high-viscosity solution after being fully hydrated, and is a biogel which integrates thickening, suspending, emulsifying and stabilizing in the world at present and has the best performance; can be used as emulsifier, stabilizer, gel thickener, wetting agent, film forming agent, etc.; is widely applied to the fields of food, medicine, chemical industry, petroleum and the like.

Improving the fermentation efficiency and reducing the fermentation cost, which is a technical problem that xanthan gum production enterprises need to continuously research and solve. The applicant has devoted themselves to the study of xanthan gum fermentation processes and has achieved certain research results. For example, the chinese patent "fermentation process of low-cost high-quality xanthan gum" adopts a membrane coupling dialysis fermentation mode, thereby avoiding the problems in fermentation due to lack of nutrients, deterioration of living environment, feedback inhibition of xanthan gum and the like, improving the fermentation efficiency, greatly improving the total yield of xanthan gum by 60% compared with a single fermentation mode.

Disclosure of Invention

Based on the prior art, the applicant has continued to optimize the xanthan gum production process, and therefore, the present application proposes a process for the production and isolation of xanthan gum.

The invention is realized by the following technical scheme.

The production and separation process of xanthan gum includes constant volume fermentation process and separation and extraction process.

Further, the constant volume fermentation process comprises the following steps:

step 1) inoculating the xanthomonas seed solution into a 300L fermentation tank filled with 200L fermentation medium for fermentation culture for 48 h;

step 2) feeding nutrient solution from the upper part of the fermentation tank at the speed of 0.2L/min, and discharging the fermentation liquor from a discharge hole at the lower part of the fermentation tank at the speed of 0.2L/min;

step 3), when the fermentation is carried out for 80 hours, the concentration of xanthan gum in the tank begins to be in a descending trend, and when the fermentation is carried out for 84 hours, the fermentation is finished; and (3) combining the fermentation liquor in the step 2) and the fermentation liquor in the fermentation tank for the subsequent separation and extraction process.

Further, the constant volume fermentation process comprises the following steps:

step 1) inoculating the Xanthomonas seed solution into a 300L fermentation tank filled with 200L fermentation medium according to the inoculation amount of 10% for fermentation culture, wherein the inoculation concentration OD₆₀₀1.5, the fermentation temperature is 30 ℃, the dissolved oxygen is controlled at 20 percent, and when the fermentation is carried out for 48 hours, the glucose concentration in the tank is measured to be 2 g/L;

step 2) feeding nutrient solution from the upper part of the fermentation tank at the speed of 0.2L/min, and discharging the fermentation liquor from a discharge hole at the lower part of the fermentation tank at the speed of 0.2L/min;

step 3), maintaining the concentration of xanthan gum in the fermentation tank at a constant concentration, starting to be in a descending trend when the fermentation is carried out for 80 hours, and stopping the fermentation tank to finish the fermentation when the concentration of the xanthan gum in the fermentation tank is reduced to 15 g/L when the fermentation is carried out for 84 hours; and (3) combining the fermentation liquor in the step 2) and the fermentation liquor in the fermentation tank for the subsequent separation and extraction process.

Preferably, the first and second electrodes are formed of a metal,

the nutrient solution comprises the following components: glucose, ammonium chloride, ethanol, arginine, methionine, VB₁。

Preferably, the fermentation medium comprises the following components: 40g/L glucose, 60g/L corn starch, 5g/L yeast powder, 10g/L oleic acid, 3g/L calcium carbonate, 1g/L magnesium sulfate heptahydrate, 1g/L dipotassium phosphate and 20mg/L, VB fulvic acid₁20mg/L，pH 7.0-7.2。

More preferably still, the first and second liquid crystal compositions are,

the nutrient solution comprises the following components: 50g/L glucose, 10g/L ammonium chloride, 10g/L ethanol, 2g/L arginine, 2g/L methionine and VB₁10mg/L。

Further, the air conditioner is provided with a fan,

the separation and extraction process comprises the following steps:

centrifuging the fermentation liquor by a high-speed disc centrifuge, collecting the upper-layer liquid, and performing centrifugation according to the volume ratio of 100L: adding a perlite filter aid into 1kg of the mixture, filtering, adjusting the pH value of the filtrate to 5.0, adding ethanol into the solution, controlling the volume percentage concentration of the ethanol in the solution to be 55%, stirring for 45min, naturally settling for 15min, centrifuging at 500rpm for 3min, and collecting precipitates; adding ethanol into the precipitate, controlling the volume percentage concentration of the ethanol in the solution at 60%, stirring for 40min, naturally settling for 15min, centrifuging at 500rpm for 3min, collecting the precipitate, and finally drying and crushing to obtain the xanthan gum product.

Preferably, the first and second electrodes are formed of a metal,

the centrifugation speed of the high-speed disc centrifuge is 5000rpm, and the centrifugation time is 4 min.

Compared with the prior art, the invention has the advantages that the following aspects are mainly included but not limited:

the invention is improved on the basis of conventional fermentation, and avoids the reduction of the activity of the strain and the reduction of the acid production efficiency caused by the excessive feedback inhibition of the concentration of the xanthan gum.

In the later stage of conventional fermentation, a mode of simultaneously feeding and discharging materials in equal amount is adopted, and the components of the fed nutrient solution are simultaneously adjusted, so that the concentration of xanthan gum is unchanged within a certain range, the feedback inhibition effect caused by overhigh accumulation of the concentration of the xanthan gum in a tank in the later stage of fermentation is prevented, the thallus activity is maintained, and the gum production period is prolonged by 36 hours in the embodiment 1 and the comparative example 1, and the gum production amount of fermentation is respectively increased by 117.7% and 61.3% compared with the comparative example 2 of the conventional fermentation mode. By comparing the fermentation mode of the example 1 with the membrane coupled dialysis, the gum yield of the fermentation of the example 1 is increased by 35 percent, which shows that the fermentation mode of the invention has more practical production value than the membrane coupled dialysis fermentation.

In the nutrient solution components of the supplementary material, glucose and ammonium chloride are used for maintaining the proliferation of the thallus cells. The right amount of ethanol has stress effect on the Xanthomonas, and can promote the Xanthomonas to generate xanthan gum polysaccharide. One of the key factors for maintaining continuous glue production of the Xanthomonas is to maintain the vitality of the bacteria, and arginine and methionine can maintain the vitality of the Xanthomonas.

In the separation and extraction process, firstly, a high-speed disc centrifuge is adopted to centrifugally remove thalli, then perlite is adopted to filter and remove small molecular weight protein, and the influence of protein impurity residues on the light transmittance of the product is avoided; the purity is improved by adopting the twice alcohol precipitation process.

The invention has simple production process, convenient operation, low extraction cost and high product light transmittance.

Drawings

FIG. 1: influence of nutrient solution components on fermentation gum yield.

Detailed Description

Those skilled in the art can modify the process parameters appropriately to achieve the desired results with reference to the disclosure herein. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the products and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations and modifications, or appropriate alterations and combinations, of the products and methods described herein may be made and utilized without departing from the spirit, scope, and spirit of the invention. For a further understanding of the present invention, reference will now be made in detail to the following examples.