SU1606532A1 - Method of nutrient medium for growing yeast - Google Patents

Abstract

This invention relates to the microbiological industry and relates to methods for preparing nutrient media primarily for laboratory growth of yeast and other microorganisms. The purpose of the invention is to increase the reliability of the method by obtaining a yeast yield adequate to the content of reducing substances (PB) in the nutrient medium, as well as to accelerate the process. The method consists in that the hydrolyzate of vegetable raw materials is subjected to neutralization, nutrient salts are added to the neutralized salt, cooled to a temperature that is optimal for growing yeast, and calcium carbonate in an amount of 10-20 wt. hours per 100 wt. h. RV. 2 tab.

Description

The invention relates to the microbiological industry and relates to methods for preparing nutrient media, mainly for laboratory growth of yeasts and other microorganisms.

The purpose of the invention is to increase the reliability of the method by obtaining a yeast yield adequate to the content of reducing substances in the medium, as well as accelerating the process.

The method consists in taking the hydrolyzed vegetable raw material either directly from the production stream or from laboratory cooking, the hydrolyzate is subjected to neutralization, since it always has an acidic reaction. Neutralization of the hydrolyzate is carried out with the same reagents as

and under production conditions (lime ammonia neutralization or pure ammonia neutral), One of the advantages of the proposed method, unlike the prototype, is that it can be neutralized. rather wide pH range: from 4.5 to 6.6, whereas in the prototype from 6.2 to 6.6, which is much higher than under production conditions for neutralization, both hot and cold hydrolyzate are used, after neutralizing neutralize is clarified by settling or filtering and nutrient salts are introduced into it - sources of phosphorus and potassium, which are usually used in production, ammophos, for example, is used as a source of phosphorus

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potassium chloride. Nutrient salt dosages are the same as those commonly used under production conditions (2.5% of PB). In addition to these nutrient salts, magnesium sulfate is introduced into the medium; in addition, during lime-ammonia neutralization

there may be a shortage of nitrogen in the environment; therefore, to replace it, the missing nitrogen is introduced into the neutral 4 lysate (from the total nitrogen content of 5% of

RB) in the form of ammonium sulfate, At g. maintaining pure ammonia neutralization is not required.

After the nutrient salts are added to the neutralized hydrolyzate, it is cooled to a temperature that is optimal for growing yeast (36-38 ° C) and calcium carbonate in powder form is used as a component optimizing the growth conditions of the yeast. calcium. The optimum dosage is 10–20 mAsocho rvo. If the dosage is less than

May 10 to May 100, PM, the calcium carbonate is not able to fully perform the function of the optimizing additive, and this leads to a lower (inadequate) yeast yield in relation to the PB (Example 2). At calcium carbonate dosage more May 20, h, at 100 May, the RV adequate yeast yield is maintained, but the ash content of the obtained yeast exceeds the limit set by GOST - 10% (Example 3). The nutrient medium obtained in this way is fully prepared for laboratory cultivation.

Example 1 In preparation for cultivation, a hydrolyzate having a concentration of reducing substances (PB) 3.2%, sulfuric acid 125.2 mg eq / l, organic acids 41.5 mg eq / l, furfural 0.05% is neutralized with ammonia water at room temperature to pH A, 6, are clarified by filtration, nutrient salts are introduced: potassium chloride in the amount of 2.5% of PB, ammonium phosphate in amount of 2.5% of PB (according to PqQs) and magnesium sulphate in the amount of 1.2% of PB, The resulting wort is diluted with water to a concentration of PB of 1.15% and added to 5 flasks. The flask is added to each flask; Calcium Nata in the amount of | 20 maCoC, per 100 May, h, RV and seed yeast in the amount of 30 May, h, per

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thirty

es

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five

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00 masoch, PB. As a seed, yeast is used as an association with a moisture content of about 75%, containing the yeast of the Candida Trichosporon genera. Growing is carried out on a rocking chair for 8 hours,

At the end of the growing process, the absolute biomass growth of the yeast is determined, which is 4.63 g / l, the content of residual rV is 0.15%, the yield of absolutely dry yeast is calculated. It is 46.3% of the assimilated pBo of true protein in yeast is 44.3%. The values given are an average of 5 parallel experiments on

To compare the effectiveness of the proposed method of preparing the nutrient medium with the prototype, the nutrient medium of the prototype is prepared, namely, potassium chloride in the amount of 2.5% of PB is added to the same hydrolyzate,

5 phosphoric acid in the amount of 3.5%. from PB, magnesium sulphate in the amount of 1.2% of PB and acetic acid in the amount of 15% of PB, then neutralized with ammonia water at room temperature

0 to pH 6.3 and diluted with water to a PB concentration of 1.2%. The resulting wort is used to grow the yeast under the same conditions as described, but the growing time is 18 hours. The absolute increase in yeast is 6.95 g / l, the content of residual PBs is 0.1%, and the yeast yield from PBs is 63.2%, the true protein content is 44.3%,

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When grown both by the proposed method and by the prototype, the pH is practically unchanged.

To compare the efficiency of the cultivation process on the hydrolysis wort according to the proposed option and the prototype with growing the yeast under production conditions, continuous yeasting of the yeast is carried out. Euelo prepared from the same hydrolyzate is used as nutrient medium in the form of a superfoe-5 stretch and KC1, in the amount of 2.5%. from PB and dilution to a PB content of 0.92%. Cultivation is carried out for 2 days at a debit of 0.25 g, a temperature of 38 s, a pH of 4.5, In the process 5

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In a laboratory fermenter, a continuous automatic feed of ammonia water is used as an additive to optimize the growing conditions. The concentration of absolutely dry yeast is 4.61 g / l, the concentration of PB in the spent culture of liquid liquid. O, 1%. Thus, the yield of absolutely dry yeast as a percentage of assimilated PBs is 50.7%.

Example 2. The test was carried out under the conditions of Example -1, but the neutralization of os11 was carried out in two steps: lime with milk to a residual acidity of 30 meq / l and ammonia water to a pH value of 4.5; 5.4 and 6.0.

The results of growing yeast under various conditions of neutralization are presented in Table. 1.-I

From the results presented in Table 1, it can be seen that the proposed method of preparing the nutrient medium for cultivation allows the laboratory cultivation to be carried out in a fairly wide pH range: from 4.5 to 6.0, depending on the set.

Example 3. The experiment was carried out under the conditions of Example 2. A nutrient medium with a pH of 5 and a RB content with varying Calcium Carbonate Dosages of 5, 10, 15,, 20 and 30 wt.% Per 100 wt.h. PB

Results are presented in

From the crawled results, it can be seen that the optimal dosage of calcium carbonate is a dosage of 10-20 mAsCo of calcium carbonate at 100 May, h. RV At a dosage of calcium carbonate 5 mAh, per 100 mAh. RV, the yield of yeast relative to RV is significantly lower than in the optimal dosage range. When dosing calcium carbonate more than 20 May, h per 100 May, h, RV, ash content of yeast

rises above the norm regulated by state standard specification,

As can be seen from the above examples, one of the advantages of the proposed method in comparison with the prototype is to obtain a yield of yeast when grown on a hydrolytic medium adequate to contain the RV in this medium. This advantage is due to the fact that in the proposed method, as a component of the nutrient medium optimizing the conditions yeast cultivation, using not acetic acid, but calcium carbonate in the amount of 10-20 wt. on May 100, h,

Rvo

Claims (1)

In addition, the advantage of the proposed method is the shorter duration of the laboratory growth process, during which almost complete assimilation takes place. RV nutrient medium. Thus, according to the prototype, the sweeping time was 18–22 hours; in the experiments, almost complete absorption of the RV was achieved in 7–8 hours. Toyoe was 2.5 times faster. The method of preparing a nutrient medium for growing yeast, including the hydrolysis of vegetable raw materials, neutralizing the hydrolyzate obtained, the introduction into it of nutrient salts and a component that optimizes the condition of assimilation of reducing substances during the cultivation, differs from increasing the reliability of the method by obtaining a yeast yield adequate to the content of reducing substances in the nutrient medium, as well as speeding up the process, as a component optimizing the conditions of assimilation reducing their substances in the process of growing, use calcium carbonate in the amount of 10-20 wt.h. on 100 ma.ch. reducing substances. Table 1 0 five 0 five Table 2 4.35 4.57 5.18 5.25 5.30 0.17 0, gg 0.15 0.11 0.09 39.3 47.6 46,9 47 49.2 7.2 6.8 10.4 11.5 16.00