RU2567814C1 - Streptococcus salivarius STRAIN VKPM V-11174, OBTAINED ON AVAILABLE MEDIUM - Google Patents

Abstract

FIELD: biotechnologies.

SUBSTANCE: strain Streptococcus salivarius M-11 with high antagonistic activity is deposited in the All-Russian Collection of Industrial Microorganisms under the registration number VKPM V-11174 and can be used for production of fermented milk products.

EFFECT: invention allows to obtain more viscous milk coagulum.

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Description

The invention relates to biotechnology and the dairy industry and is a new strain of mesophilic streptococcus, intended for the production of dairy products and bacterial preparations.

A known strain of Lactobacillus salivarius CNCM I 1794, with a strong immunomodulating effect, as well as strains of Lactobacillus salivarius AN102, AN103, AN105, AN109 or AN110, which have the properties of a probiotic, are intended for the preparation of a probiotic preparation used, in particular, for use in immunological procedures vaccination.

The disadvantage of these strains is low antibiotic activity against opportunistic and pathogenic microflora.

The objective of the invention is the creation of a fermented milk product using lactobacilli, on accessible nutrient media with high antagonistic activity.

The problem is solved by using nutrient media of dense and liquid consistency: sterile skim milk, hydrolyzed milk (pH 6.8–7.0), unsalted cheese whey with a content of at least 4.0% sugar.

A local strain of Streptococcus salivarius is isolated from raw milk sour milk.

The identification of the strain was carried out according to the method described in the book of L.A. Bannikova (1975).

The strain is deposited in the All-Russian collection of industrial microorganisms and has a number VKPM B-11174.

The strain of Streptococcus salivarius VKPM B-11174 has the following characteristics:

1. Cultural and morphological:

- optional anaerobic;

- gram-positive cocci;

- diameter 0.5-0.7 microns;

- motionless;

- located - chains of coccoid cells;

- do not form endospores.

On the surface of the agar medium (MRS agar) after 24 hours at a temperature of 37 ° C form:

- round colonies;

- point size;

- the nature of the contour of the edge is even;

- relief is convex;

- the surface is smooth;

- White colour;

- the structure is homogeneous;

- consistency - pasty.

The study of the cultural or morphological properties of the selected strain of lactic acid microorganisms was carried out on a dense nutrient medium - agarized milk and MRS agar.

2. Physiological and biochemical:

- milk fermentation rate - 6 hours;

- the limit of acid formation is 119 ° T;

- the strain ferments glucose, galactose, lactose, maltose, dextrin;

- grows in milk at a temperature of 37-40 ° C;

- grows in hydrolyzed milk containing NaCl (4%);

- grows in meat-peptone broth (at pH 9.2);

- grows in hydrolyzed milk with bile content (20%, 30%, 40%);

- grows in milk containing methylene blue (0.0005%, 0.005%);

- withstands heating for 30 minutes at a temperature of 55 ° C.

The product synthesized by the strain is lactic acid, antibiotic substances.

3. Antibiotic activity:

- the diameter of the zone of growth suppression in relation to the representative of the pathogenic microflora Staphylococcus aureus was 25 mm;

- the diameter of the zone of growth inhibition in relation to the representative of opportunistic microflora of Escherichia coli was 24 mm.

The antibiotic activity of the strain of Streptococcus salivarius VKPM B-11174 was determined on solid nutrient medium (MPA) by agar diffusion.

The method, conditions and composition of the media for long-term storage of the strain - lyophilization; storage at a temperature of 4-6 ° C; environments: MPS; Rogosa et. al .; milk with chalk; milk with yeast autolysate, glucose, litmus, liver extract and CaCO ₃ .

The method, conditions and composition of the media for the propagation of the strain at a temperature of 37 ° C; medium: MPS agar; skim milk, unsalted cheese whey with a content of at least 4.0% sugar.

Optimum conditions and composition of the medium for fermentation - temperature 37 ° C; Medium: MPS agar, unsalted whey whey with a content of at least 4.0% sugar, skimmed cow's milk.

The proposed new strain of Streptococcus salivarius VKPM B-11174, isolated from raw milk fermented milk, is well adapted to local conditions, easy to cultivate and store, can be used in the production of fermented milk products, is non-zoo and phytopathogenic, and is not dangerous for other reasons.

Example. Preparation of a fermented milk drink by the tank method using bacterial starter culture, which includes the proposed strain of Streptococcus salivarius VKPM B-11174.

To prepare a laboratory starter culture in 100 ml of sterilized skim milk at 37 ° C make one portion of the starter culture, consisting of Streptococcus salivarius VKPM B-11174 and L.bulgaricus. Fermented milk is kept at the indicated temperature for 6-8 hours until a clot forms.

Production ferment is prepared by adding 100 ml of laboratory ferment in 10 liters of sterilized skim milk. Fermented milk is kept at 37 ° C for 6-8 hours until a clot forms.

Manufacturing sourdough is characterized by a clean, sour-milk taste, a uniform viscous consistency, titratable sourdough acidity of 85 ° T, micropreparations of cocci chain and single sticks.

To prepare a fermented milk drink, 3-5% of the production yeast is added to the prepared milk. The ripening process takes place at 37 ° C for 6-8 hours until a dense clot forms. The resulting product is mixed and served on bottling.

Due to its pronounced biological and antibiotic properties (the ability to form a viscous milk clot, the diameter of the zone of inhibition of growth of Staphylococcus aureus is 25 mm, Escherichia coli is 24 mm), the strain is of industrial value for the dairy industry.

Claims (1)

Strain Streptococcus salivarius VKPM B-11174 used in the production of dairy products.