SU1084298A1 - Method for preparing biomass of fodder yeast - Google Patents

Abstract

METHOD FOR OBTAINING BIOMASS FOR FEED YEAR, envisaging. growing them in a nutrient medium containing cellulose-containing plant material hydrolyzate as a carbon source, sources of nitrogen and phosphorus: and a growth stimulator, under conditions of aeration of the environment, which is because, in order to increase the biomass yield, as a stimulator growth using deoxyribonuclease in an amount of 0.1 mg / l of medium.

Description

as you

) 00 The invention relates to the microbiological industry, namely the production of fodder yeast. A known method of producing fodder yeast by cultivating them on a nutrient medium containing sources of carbon, nitrogen, and mineral salts in the presence of cellulolytic enzymes {/ 11 "The disadvantages of this method are the low yield of yeast. The impossibility of separating yeast from non-hydrolyzed plant residues, low protein content in the resulting feed. The closest in technical essence and the achieved effect to the proposed is a method of obtaining biomass of fodder yeast, which involves growing them on a nutrient medium containing cellulose-containing plant material hydrolyzate as a carbon source, source of nitrogen and phosphorus and a growth stimulator, under conditions of aeration of the medium. According to this method, quinone polycarbonate ammonium salts are used as a growth stimulator. acids. . The disadvantage of this method is low biomass yield. The purpose of the invention is to increase the yield of yeast biomass. The goal is achieved by the fact that according to the method of obtaining biomass of fodder yeast, which involves growing them in a nutrient medium containing hydrolysis of cellulose-containing plant material as a carbon source, sources of nitrogen and phosphorus and growth stimulator, under conditions of aeration of the medium as a stimulus growth using deoxyribonuclease in amounts of 0.1 mg / l of medium. The essence of the method is as follows. Deoxyribonucleases are a group of enzymes capable of depolymerizing d-hydroxyribonucleic acid. Under the action of deoxyribonuclease on living cells, an increase in the synthesis of deoxyribonucleic acid is observed in them. Low concentrations of deoxyribonucleases, which are close to the concentration of enzymes in a living cell, have a stimulating effect on the synthesis of deoxyribonucleic acid, and consequently, on the growth and reproduction of cells. Example 1. To a nutrient medium (wood hydrolyzate with the amount of PB 0.98-1.0%, containing mineral salts necessary for the growth of yeast in terms of Pj0 250260 mg / l No. j 480-490 mg / l, pH 4.2- 4.4) a commercial preparation of the hydrolytic enzyme pancreatic Deoxyribonuclease is added. Contribute 25. Cand.ada scottii KS-2 in the amount of 25. g / l of medium. The cultivation of the yeast is carried out in a laboratory inoculant with a capacity of Zle and a working volume of 1 l of medium at 37-38 ° under aeration conditions for 3.5 hours. The data obtained are given in Table. 1. Thus, as can be seen from the data table. 1, the maximum increase in yeast biomaCl is observed when the enzyme is added at a concentration of 0.1 mg / l of medium. Example 2. The enzyme is added to the nutrient medium in an amount of 0.1 mg / l of medium (which corresponds to an activity of 1500 units). A commercial crystalline preparation is used, as well as a technical preparation of the enzyme (ammonium sulfate fraction). Next, the process is carried out analogously to example 1. The data obtained are given in table. 2. As can be seen from the data of Table 2, in the presence of the enzyme, the biomass yield of yeast increases by 16.5–18% by weight and by 17.8–18.5% by weight of absolutely dry weight. Acceleration of substrate consumption in the experimental Variant, as compared with the control one (according to the residual RV), indicates the intensification of the yeast growing process under the action of the enzyme (15-16.7%). The use of a commercial drug and technical drug Deoxyribonuclease gives comparable results. This makes it possible to recommend the use of a technical preparation as cheaper. EXAMPLE 3. In order to study the effect of deoxyribonuclease on the yield of yeast under conditions that are as close as possible to production, the yeast is continuously cultivated in the presence of a technical preparation of the enzyme at a concentration of 0.1 mg / l of medium. The process is carried out analogously to example 1. After 2 h after seeding, the transfer to the detachable-to-addicative method of cultivation at the flow rate of the medium 130-320 ml / h, the wire selection of the yeast suspension hourly. Growing time 70 h.

In the course of continuous cultivation, deoxyribonuclease is introduced together with fresh nutrient medium at a rate of 0.1 mg / l of medium. The data obtained are presented in Table. 3

K - control variant - the yeast was cultured without an enzyme.

0ts- experimental option - yeast

cultured in the presence of an enzyme.

The content of total protein in yeast obtained is 50–52%, true protein 44–4. The effect of enzyme concentrations on yield

Concentration

Crude weight, g / l enzyme, mg / l, medium

ten

1.0

0.1

0.01

ABOUT

As can be seen from the table. 3, in the presence of the enzyme, the yeast biomass yield is increased by 41.4% by wet weight, by 59.2% by absolutely dry weight. The difference in the volumes of the medium that passed through the control and experimental inoculum after 70 h of cultivation with close average values of the residual medium RV in the control and experimental variant indicates an intensification of the process of growing yeast (by 20.5%).

Thus, the proposed method of growing fodder yeast as compared to the known increases the biomass yield by 4.4% with the use of a ferment concentration 10,000 times lower.

Absolutely dry weight, g / l

9.16 9.27 10.82 9.15 9.18 Table1 of biomass $ 1.084298, Effect of deoxyribonuclease drug on Tabal and c 2 biomass yield

Commercial 15% preparation - 0.20 0.17 rat Technical product (ammonium sulfate fraction) 0.18 0.15 16.7% 32.70

To - control option - yeast cultured bnh enzyme.

Ofj- experimental variant - yeast was cultured in the presence of an enzyme.

The content in the resulting yeast total protein 50-52%, true

protein 44-46%.

The implementation of the method in conditions of continuous cultivation

18.5%

T a b l and c a 3 36.36 43.10 16.6% 9.18 10.32 17, 38.63 18.1% 8.07 9.66

Claims (1)

'METHOD FOR PRODUCING FODDER YEAST BIOMASS, providing. growing them on a nutrient medium containing a hydrolyzate of cellulose-containing plant materials as a carbon source, sources of nitrogen and phosphorus and a growth stimulator, under conditions of aeration of the medium, which involves the use of deoxyribonuclease as a growth stimulator in order to increase the biomass yield the amount of 0.1 mg / l of medium. ’