SU1544803A1 - Strain of rhadotorula glutinis yeast used for feeding hydrobionts - Google Patents

Abstract

This invention relates to the microbiological industry and can be used in fish farming. The strain of yeast RHODOTORULA GLUTINIS VAR. GLUTINIS deposited as VKMP U-608, develops on a mineral medium with ethanol, not containing growth factors, has a high biomass yield, aerobic, develops at a temperature of 12 to 43 ° C, PH 2.5-7.0, withstands the salinity of the environment up to 2 mol / l NACL and freeze drying.

Description

The invention relates to the microbiological industry and concerns a new yeast strain used to feed aquatic organisms in fish-breeding ponds in ethanol.

Ethanol is a promising feedstock for the microbiological industry. Industrial yeast strains — producers of proteinaceous and vitamin substances — should possess not only a fairly high growth rate and biomass yield, but also such valuable production characteristics as tolerance to high temperature (growth at 12-43 C), acido-tolerance (growth at pH 2 , 5-7,5), no need for growth factors, since the set of these,

properties makes the yeast strain competitive with respect to the bacterial microflora in high-tonnage production conditions. The thermotolerance of the strain not only reduces the energy consumption for cooling the plant fermenter, but also leads to a decrease in the level of extraneous infection when growing yeast in non-sterile conditions.

The use of yeast as a live feed for aquatic organisms in order to increase the productivity of fish ponds, and not as a protein-vitamin supplement, imposes on the strain a number of additional requirements that these strains do not possess.

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The main ones of these requirements are as follows: the biomass of the yeast strain must well stimulate the growth of hydrobionts under pond conditions; the strain must multiply in ponds, since it allows to involve into the food chain of this ecosystem those organic and mineral compounds which usually do not participate in the circulation of the pond ecosystem; The strain must retain a high degree of viability at full height, since its use in fish farming conditions from a technological point of view is most convenient as a dry powder.

The proposed strain Phodotoru a gj-utinis var. glutinis VKPM U-608, developed in a mineral medium with ethnol that does not contain growth factors, has a high biomass yield (70-75% of ethanol used). The indicated yield is achieved at a dilution rate of the medium up to 0.35 h

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At pH 3.5-4.0 and 25-30 ° C. At the same time, the proposed strain develops well in the conditions of fish ponds, stimulates the growth of hydrobionts and maintains freeze drying.

Cultural and morphological features. On the wort agar, the strain is formed. Large, intensely pink colonies with a high center, shiny, short, slightly striated. Cells Oval or spherical. Sizes: 4.0-10, 5-5.0 microns. Psevdomitseli Ye form.

In the liquid malt wort a precipitate is detected, it does not form a film. Medium and acetate agar spores were not found.

Physiological signs. Aerobe, developing 12–43 ° C (maximum growth at 28 ° C), pH 2.5–7.0 (maximum maximum at pH 3.0–5.0), will sustain the salinity of the medium up to 2 mol / L NaCl Sugar fermenting. Assimilates glucose, maltose, sucrose, raz oz, melysitose and ethanol.

Attitudes towards vitamins, Strain grows well in a non-vitamin environment. The strain is defined as Rhodotoruls glutinis var. glutinis on the basis of the gest, edited by Lodder.

Example 1. Strain Rhodotorula glutinis var. glutinis VKPM U-608 grown in the fermenter ANKUM-2 (working volume of 1.5 liters) at a temperature of

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C and pH 5.0 under continuous culture conditions with growth limiting with ethanol on medium 11-E.

The cultivation is carried out at a dilution rate of 0.35 hours. The yield of absolutely dry substances from a given ethanol is 75%. The crude protein content is 56%. The amino acid composition of the protein is as follows,%: asparagine 4,059; threonine 2.074; serine 2,064; glutamine 7.295; Proline 2,158; glycine 2,369; alanine 3,623; valine 2,619; methionine 0.973; isoleucine 1,956; leucine 3.562; tyrosine 3,751; phenyllalanine 2,410; histidine 1,173; lysine 3.737; arginine 5.298; cystine 1,400. After fermentation, the resulting biomass is freeze-dried. The number of living cells in the preparation is 60-70%.

PRI mme R 2. Strain Rhodotorula glitinis var. Glutinis VKPM U-608 is grown in a fermenter at 28 ° C and pH 5.0-6.0 under periodic cultivation conditions with ethanol as a carbon source in 8-E medium.

The yield of absolutely dry substances from the specified ethanol is 70%, the content of crude protein is 51%.

After fermentation, the resulting biomass is freeze-dried, while the number of living cells in the preparation is 60-70%.

Example 3. Biomass of the yeast strain Rhodotorula glutinis var. Glutinis VKPM U-608, grown in a batch or continuous culture, is freeze-dried and introduced into fish ponds as a dry powder. The results of the studies showed that in the ponds into which the aqueous yeast Rhodotorula glutinis var. glutinis VKPM U-608, average biomass of zooplankton was 10.86 g / m, zoobenthos - 14.64 g / m, and their production, respectively, 114 and 50.07 g / m. In the control ponds, the average biomass of zooplankton during the growing season was 7.97 g / m and that of zoobenthos was 10.5 g / me, and their production was 70.25 and 36.76 g / m, respectively.

At the same time, the proposed strain possesses some more production valuable indicators, such as halogen tolerance and pigment content.

The first ich of these properties allows the biomass to be increased under conditions of reduced sterility requirements, since when 1 mol of NaCl salt is added to the medium, the growth rate of the strain is reduced by a small amount, and the bacterial microflora that infect the fermenters does not develop.

The second of these indicators is also valuable because the pigments formed by the strain belong to the group of carotenoids, which are known to be provitamins of the vitamins of group A.

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Thus, the strain Rhodotorula glutinis var. glutinis VKPU U-608 is capable of developing in an environment with ethanol without growth factors, with indicators close to those known in the industrial strains used, but it has several advantages that make it valuable in production when used as a factor in enhancing the biological productivity of fish ponds.

Claims (1)

Invention Formula The strain of yeast Rhodotorula glutinis var. glutinis VKMP U-608, used to feed aquatic organisms.