RU2146287C1 - Method of selenium-containing spirulina producing - Google Patents

Abstract

FIELD: biotechnology, microbiology. SUBSTANCE: invention relates to the method of producing selenium-containing spirulina at the content of organic (bioavailable) selenium 6.15-6.5 g/kg. In the process of spirulina culturing selenium inorganic salt is added by two portions: the first portion - at the last quarter of logarithmic phase growth and the second portion - at the stationary phase growth. Method ensures to increase the content of bioavailable selenium, decrease time of technological process carrying out and amount of selenium salt added. Obtained product can be used in food and microbiological industries. EFFECT: improved method of producing, increased content of bioavailable selenium. 7 ex

Description

 The invention relates to microbiology, food industry, agriculture and can be used to obtain biologically active substances based on microalgae.

 A known method of producing selenium-containing biomass of spirulina [1], according to which the selenium-containing biomass of spirulina is obtained by adding an inorganic salt of selenium in a nutrient medium, followed by incubation of spirulina on it.

 The disadvantages of this method include the low content of organic selenium in the resulting biomass, comprising 20-200 microns / kg of dry biomass weight.

 A known method of producing selenium-containing biomass of spirulina [2] by introducing a salt of inorganic selenium into the nutrient medium for 5-10 days, when the culture entered the beginning and the first half of the logarithmic growth phase. This method is advisable to choose for the prototype.

 The disadvantages of the prototype include the low content of organic selenium in the resulting biomass of spirulina, averaging 5.59 g / kg of dry biomass weight, the duration of cultivation (30 days).

 The task of the invention is to obtain biomass of spirulina with a high content of organic selenium.

 Another task is to reduce the time of the process.

 The technical solution of the problem is achieved by the fact that the inorganic salt of selenium is introduced into the nutrient medium fractionally, namely, the first portion of the salt is introduced in the last quarter of the logarithmic growth phase, the second - when entering the stationary growth phase.

 The proposed method using these methods of introducing salts of inorganic selenium into the microalgae nutrient medium ensures the achievement of a technical result: a high content of organic, bioavailable selenium and at the same time a significant reduction in the process time.

 Culture growth is on an S-shaped curve. The achievement of the technical result is based on the use of the previously unknown property of the spirulina culture to absorb selenium to the maximum at optimally low concentrations of antagonists: sulfur and bicarbonate ions in the medium. This moment is achieved in the last quarter of the logarithmic phase of culture growth, and not at the beginning of cultivation or in the first half of the logarithmic phase of culture growth, as in the previously known methods.

 From the scientific, technical and patent literature, the authors are not aware of technical solutions that could in the proposed combination of essential features allow to obtain the technical result given in this application.

 Therefore, the present invention meets the criteria of novelty and patentability. When studying technical solutions, the features that distinguish the invention from the prototype were not identified from the prior art, and therefore they provide the invention with the criterion of "inventive step".

 The method is as follows.

Spirulina is grown in a cumulative, intensive mode in 80 L semi-industrial cultivators equipped with fluorescent lamps, with illumination of 12 - 15 thousand erg / cm ² , temperature of 28 - 30 ^o C, pH of 8.0 - 8.5. By measuring the optical density of the culture fluid at the FEC, the concentration of spirulina cells during growth is determined from the calibration curve. The first portion of selenium-containing salt is introduced at the time of reaching a cell concentration of 0.8 - 1 g / l, which characterizes the yield of culture in the last quarter of the logarithmic growth phase. The concentration of cells upon reaching the stationary phase of growth is 1.2 - 1.5 g / L. Upon reaching this concentration, selenium-containing salt is re-added. After 7 days, the biomass is separated by filtration, washed with physiological saline (in a five-fold volume), dried and ground.

 A product is obtained with a selenium content of 6.15-6.5 g / kg. To use it as a biologically active food supplement, the resulting concentrate is mixed with dry spirulina biomass in order to bring the selenium content to the permitted pharmacopoeial standards.

 The following examples illustrate the achievement of technical results.

Example 1 control (prototype). The cultivation of the spirulina strain Spinilina platensis (Nordst) Geiti. Ippas B-437 is carried out in semi-industrial cultivators with a volume of 80 l on a nutrient medium, presented in the prototype. On the 5th day of incubation, when the culture is at the beginning of the logarithmic growth phase, inorganic salt of selenium Na ₂ SeO ₃ in the amount of 50 mg / L of Medium is added to the medium, after which the incubation of the culture is continued until 30 days from the start of incubation. The biomass is separated from the medium by filtration and, without washing with physiological saline, is dried. An organic selenium content of dry spirulina biomass of 5.59 g / kg is obtained.

 Example 2. Spirulina is seeded and incubated according to example 1. Inorganic salt of selenium in an amount of 25 mg / l is introduced into the nutrient medium in the last quarter of the logarithmic growth phase (cell concentration 0.8 g / l), and the second portion of selenium-containing salt is added at the time reaching the stationary phase of growth (cell concentration 1.2 g / l) at a concentration of 15 mg / l. Cultivation is carried out up to 7 days. The biomass is separated by filtration, washed with physiological saline in a five-fold volume and dried. The concentration of organic selenium in the dry spirulina biomass is 6.5 g / kg, in the control - 5.59 g / kg.

 Example 3. Sowing and culturing are carried out according to example 1. The resulting biomass is separated by filtration and, without washing with physiological saline, dried. The total concentration of organic and inorganic selenium in the resulting spirulina sample, not washed with physiological saline in a five-fold volume, is 8.3 g / kg. The content of organic selenium in the biomass of spirulina washed with physiological saline in a five-fold volume is 6.15 g / kg (example 1).

 Example 4. Spend sowing and cultivation according to example 1.

When the last quarter of the logarithmic growth phase is reached at a cell concentration of 0.89 g / l, the inorganic salt of selenium Na ₂ SeO ₃ (sodium selenite) is added in an amount of 15 mg / l, cultured until the stationary growth phase of the culture is reached (cell concentration 1.3 g / l) and additionally make an inorganic salt of selenium Na ₂ SeO ₃ (sodium selenite) in an amount of 20 mg / l.

 Cultivation is continued up to 10 days from the start of incubation. Spirulina biomass is separated from the medium by filtration, washed with physiological saline in a five-fold volume and dried. Get the content of organic selenium in the dry biomass of spirulina, equal to 6.6 g / kg, in the control - 5.59 g / kg

 Example 5. Spend sowing and cultivation according to example 1.

When the last quarter of the logarithmic growth phase is reached at a cell concentration of 0.88 g / l, the inorganic salt of selenium Na ₂ SeO ₃ (sodium selenite) is added in an amount of 10 mg / l, cultivated until the stationary growth phase of the culture is reached (cell concentration 1.3 g / l) and additionally add an inorganic salt of selenium Na ₂ SeO ₃ (sodium selenite) in an amount of 30 mg / l.

 Cultivation is continued up to 12 days from the start of incubation. Spirulina biomass is separated from the medium by filtration, washed with physiological saline in a five-fold volume and dried. Get the content of organic selenium in the dry biomass of spirulina, equal to 6.55 g / kg, in the control - 5.59 g / kg.

 Example 6. Spend sowing and cultivation according to example 1.

Upon reaching the last quarter of the logarithmic phase of growth at a cell concentration of 0.90 g / l, an inorganic salt of selenium Na ₃ SeO ₃ (sodium selenite) is added in an amount of 15 mg / l, cultivated until the stationary phase of growth of the culture is reached. When the concentration of cells in the stationary growth phase is 1.2 g / l, an inorganic salt of selenium Na ₂ SeO ₃ (sodium selenite) is added to the culture fluid in an amount of 15 mg / l and, in addition, when the concentration of cells is 1.5 g / l, an inorganic salt of selenium Na ₂ SeO ₃ (sodium selenite) in an amount of 15 mg / L.

Cultivation is carried out up to 10 days from the start of incubation. Spirulina biomass is separated from the medium by filtration, washed with physiological saline in a five-fold volume and dried. Get the content of organic selenium in the dry biomass of spirulina, equal to 6.7 g / kg, in the control - 5.59 g / kg,
As can be seen from the above examples, the concentration of organic selenium upon fractional application of the inorganic salt 6.5-6.7 g / kg (Example 3) is higher than upon a single application of 6.15 g / kg.

 From the examples it is seen that the selenium content in the biomass not washed with physiological saline is 8.3 g / kg (Example 4), and in the prototype method it is 5.59 (Example 2). And even in biomass washed with physiological saline, the content of organic selenium is 6.15 g / kg (Example 1) higher than that of the prototype 5.59 g / kg (Example 2).

 In the process of washing, mechanically settled selenium is removed, which is not absorbed by the body.

The fraction of the introduction of selenium-containing salt (sodium selenite -Na ₂ SeO ₃ ), as in examples 3, 5, 6, 7, allows you to reduce the amount of expensive salt of Na ₂ SeO ₃ from 100-50 mg / l to 38-45 mg / l, which accordingly, reduces the cost of the final product, and also reduces the duration of the process from 30 days to 12-7 days.

 The resulting batches of spirulina enriched with selenium are raw materials for the feed, food, agricultural and pharmaceutical industries.

 The method was carried out on a semi-industrial installation and its transfer to industrial volumes is not difficult for plants of the microbiological and food industries.

Literature
1. DE, application 3421644, A 61 K 33/04, 1985.

 2. RU, patent 2096037, C 12 N 1/12, 1997.

Claims (1)

 A method of producing selenium-containing spirulina, comprising the cultivation of spirulina with the introduction of an inorganic salt of selenium, characterized in that the inorganic salt of selenium is introduced in the last quarter of the logarithmic growth phase and in the stationary.