SU1386658A1 - Strain of streptococcus acetoinicus bacteria used for producing sourish milk products - Google Patents

Abstract

. Strain (III) Streptococcus acetoinicus A is crawled from the collection strain Streptococcus acetoinicus 18ac. 21 by exposure to a chemical mutagen. It has the ability to actively develop in milk without a sharp increase in acidity and high proteolytic activity (PA). It grows on liquid hydrolyzed milk, forming a dregs, as well as on agar with hydrolyzed milk. When it develops in milk to contain 10 cells in a ml, it does not form a clot. The size of cells is 0.5-0.7 microns, the shape of cells is cocci, arranged in two and in short chains. On the agar forms shiny surface colonies with a diameter of 0.3-1.5 mm and deep colonies in the form of boats. W develops within the temperature range of 28-43 ° C. The optimal growth temperature. It multiplies in hydrolyzed broth with a pH of 9.2 and 9.6; 6.5% NaCl, 30% and 40% bile. Ferments sucrose, does not ferment lactose. Resistant to penicillin. The maximum acidity of 40 tons. 5 table. with S (L with 00 05 05 el 00

Description

ten

The invention relates to the dairy industry, namely to biotechnology, is a new strain of lactic acid bacteria and can be used in the production of fermented milk products, yaktov, beverages, cheeses.

The purpose of the invention is to obtain a new strain of lactic acid bacteria Streptococcus acetoinicus, which is able to actively develop in milk without a sharp increase in acidity and with high litholytic activity. The strain was obtained from the collection strain S, acetoinicus 18-21, 5 stored in the UkrNI collection No. 1 co-molprom, using chemical mutagenesis. Differences between the original strain and that obtained were obtained when determining growth in hydrolyzed milk with different pH, bile, phenol, and salt. The main indicators of the mutant mesophilic lactic streptococcus S. acetoinicus VKPM B-3548 (a) in comparison with the original Si acetoinicus 18ac. 21 are presented in table. 1-3.

As can be seen from the table. 1 strain Str. acetoinicus is more resistant to adverse environmental conditions in comparison with baseline - it multiplies in a medium with a pH of 9.2 and 9.6; 6.5% NaCl; 30 and 40% of uelchi, the strain ferments sucrose and does not ferment lactose (Table 1), resistant to penicillin (Table 2).

No drying culture can be stored in a sealed ampoule more than 3 years.

Identification of the strain was carried out, according to the main morphological, cultural and physiological and biochemical properties according to the characteristics of Pimenova MN, who proposed to isolate Str. acetoinicus in a separate species.

Strain.Str. acetoinicus a, stores20

with in the museum of cultures of microorganisms of the Institute VNIIGenetika under the lecture number VKPM B-3548.

Morphological signs. The size of cells is 0.5-0.7 microns, the shape of cells is cocci, arranged in two and in short chains, gram-positive. Cultural signs. It grows on liquid hydrolyzed milk, forming a dregs, as well as on agar with gzdrolizovanny milk. When breeding in. Milk to. cell content 10 per 1 ml of the clot does not form.

Physiological and biochemical properties 25 (tab. 1-3). The strain grows at a temperature of 28-43 ° C. The optimum growth temperature.

The use of a strain in combination with thermophilic and mesophilic lactic acid bacteria increases their proteolytic activity, stabilizes acidity and allows to improve the taste and texture of the finished fermented milk product,

Dp illustration achievable by 30

The significant difference between the mesedu is 35 in the table. 4 prev

No drying culture can be stored in a sealed ampoule more than 3 years.

Identification of the strain was carried out, according to the main morphological, cultural and physiological and biochemical properties according to the characteristics of Pimenova MN, who proposed to isolate Str. acetoinicus in a separate species.

Strain.Str. acetoinicus, stores

with in the museum of cultures of microorganisms of the Institute VNIIGenetika under the lecture number VKPM B-3548.

Morphological signs. The size of cells is 0.5-0.7 microns, the shape of cells is cocci, arranged in two and in short chains, gram-positive. Cultural signs. It grows on liquid hydrolyzed milk, forming a dregs, as well as on agar with gtsdrolizovanny milk. During reproduction in milk, it does not form a clot to contain 10 cells per 1 ml.

Physiological and biochemical properties (table. 1-3). The strain grows at a temperature of 28-43 ° C. The optimum growth temperature.

The use of a strain in combination with thermophilic and mesophilic lactic acid bacteria increases their proteolytic activity, stabilizes acidity and allows to improve the taste and texture of the finished fermented milk product,

Dp illustrations achieved by

The obtained and obtained strains were found in determining the limiting acidity and proteolytic activity (Table 3).

As can be seen from the table. 3, the resulting strain in the process of viability produces lactic acid 3.9 times less than the original strain over the same period of time. Established

that the proteolytic activity of the strain-45 of the political activity is 3 times more than the initial one.

The strain may be stored in hydrolyzed milk enriched with 4% sodium citrate, 1% glucose and 2% yeast autolysate. The culture was inoculated in an amount of 10%, incubated at 17–18 h, then stored at 4–6 ° C for 1 month. After this period, the strain is transplanted into a fresh medium. In addition to the liquid storage medium for the strain, agar with hydrolyzed milk enriched with the indicated components can be used. Dried sublimadiontavlen quality indicators of skim milk, fermented with a combination of strains of S. thermophilus and S. diacetilactis with the addition and without the addition of the proposed strain.

From the data table. 4, it can be concluded that the combination of strain a. with S. thermophilus and S. diacetilactis leads to a sharp increase in acidity, and to improve the taste and texture of the test samples in comparison with the control ones (without strain a). The percentage increase in proteolytic activity of the species, the higher the content of strain a in the starter. The most characteristic effect of the strain ai has on the culture of Str. diacetilactis I Flax.

The preparation of samples for the determination of the proteolytic activity of the strains under study was carried out according to the Hung method. The determination and calculation of the proteolytic activity of the strains was carried out according to the method for determining the activity of hydrolytic enzymes. The preparation of strain-forming media according to GOST. Titrated acidity was determined by means of titration with decinormal alkali using phenolphthalein indicator, acid activity of acidification, the maximum acidity, growth in hydrolyzed broth with different content of NaCl ,. bile, phenol, carbohydrate digestion - by known methods.

The proposed strain B. acetoini-CUS a can be used in a compound of different starters, which, depending on the target product, differ in both species and strain composition.

Example. Preparation of de-fatty fermented milk drink using S. acetoinicus strain

L

5 tons of skimmed milk are pasteurized, cooled down and 3% of production ferment is added to the bottom.

The preparation of the starter is carried out in two stages: first, the laboratory starter is prepared, then the production one.

Laboratory ferment is prepared on sterilized milk by adding 3% symbiosis and incubation at 30 ° C until a clot forms. Symbiosis is characterized by the following composition: S. lactis 121, S. thermophilus ri-24, S. diacetilactis 1 Len. and S. acetoinicus a. The laboratory ferment is characterized by a dense clot, a clean, fermented milk flavor with a pronounced aroma; in a microscopic preparation, diplococci and chains of various lengths are found.

Production ferment is prepared on sterilized or pasteurized milk, fermenting it with 5% laboratory ferment at 30 ° C. The sourdough milk is mixed and held until a clot forms. Production starter is characterized by a dense clot, a clear, fermented milk taste. Titrate ferment starter 86 T, microscopic drug - diplococci and streptococci.

After the production ferment is added to the skimmed milk, the mixture is stirred and kept under acidity until a clot forms. The finished product is stirred

five

five

0

P

five

five

0

five

while cooling and sent for bottling.

Characteristics / product are presented in table. five.

Example 2. Preparation of sour cream with a fat content of 20% using the strain S. acetoinicus a.

970 kg of cream with a fat content of 20.62% are pasteurized at 95 ° C with a holding time of 20 s, cooled to 24 ° C and 30 kg of production ferment are added, which is prepared in two steps.

Laboratory ferment is prepared on sterilized milk, inoculating its 3% symbiosis of the following composition: S. cremoris 8P, S. cremoris 40, S. diacetilactis 16 and S. acetoinicus a2. Inoculated milk is kept at 25 ° C until a clot forms. The leaven is characterized by a dense viscous clot, a clear, dairy-flavored taste with a pronounced aroma; in the microscopic preparation, diplococci and short chains are found.

Production ferment is prepared on sterilized milk or pasteurized milk, in which 4% of the laboratory ferment is added, and incubated at 25 s until a clot forms. Production ferment is characterized by a dense viscous clot, an acidity of 87 ° T, and a pure, fermented milk taste.

The sourdough cream is stirred and held at 24 ° C until a clot forms with an acidity of 72 ° C. The fermented product is stirred while cooling and directed to bottling.

Characteristics of the product are presented in table. five..

PRI me R 3. Preparation of a fermented milk drink with a fat content of 1.5% using S. acetoinicus strain a.

950 kg of milk with a fat content of 1.67% is pasteurized with an aging time of 15 s, cooled to 28 s and 50 kg of production ferment prepared in two stages is introduced into it.

Laboratory ferment is prepared on sterilized milk, which inoculates 4% of the symbiosis of the following composition: S. lactis L-12, S. cremoris 40, S. thermophilus 15, S. acetoinicus a. After inoculation, the milk is kept at 28 ° C until a clot forms. The laboratory ferment is characterized by a dense viscous clot, pure sour milk taste, in the mic-) oskopic preparation is detected (iH diplococci and chains of different

jWtHHbl,

To prepare the production ferment, pasteurized or sterilized milk is added with 5% laquerous starter and incubated at 28 ° C until a clot forms. Production ferment is characterized by a dense viscous clot acidity of 85 ° t with a pure, sour-milk taste.

After the production ferment is added to the milk, the mixture is stirred and kept at 28 ° C until the clot forms acidity. The resulting product is stirred with simultaneous cooling and directed to bottling.

Characteristics of the finished product are presented in table. five.

Growth in hydrolyzed milk with a pH of 9.2

9.6

Growth in broth 4.0

6.5

Growth B broth whose%: 20.0

30.0

40.0

Growth in scrap broth,% t 0,2

Fermentation of coal alcohols: lactose

sucrose

The data presented in table. 5 indicate that using itam S. acetoinicus, in comparison with the well-known S. acetoinicus 18-21 ttamma (stored in the UkrNIIm somolproma collection) allows to improve the consistency of fermented milk products, to intensify the fermentation process, as well as to increase their content aromatic substances that have a positive effect on the taste of the target products, and the content of proteolysis products of proteins that increase their biological value.

Claims (1)

Invention Formula Bacterial strain Streptococcus acetoinicus BKIIM B-3348 used for the production of fermented milk products. I. Table 1 + f + + + + arabinose maltose raffinose glucose rhamnose mannitol G1 Sensitive n Stable Page epicin Kanamycin Indicators Extreme acidity Lactic acid ,,% Proteolytic activity, µm / ml 1386658 8 Continuation of table 1 table 2 Sensitive Steady sensitive P Stable t a b l and yes 3 Str. acetoini- cus 18-21 128 0.702 0.084 Taste smell Consnstvo Pure Sour Milk Pure Sour Milk Pure Sour Milk Homogeneity-Insufficient-Homogeneous-Insufficient-Odiorod-Insufficient-on-odnogorod- on-is dense and a mixture of homogeneity from the compartment gg-tanoov- on tattered sate different orotki Titratable content, 85 88 Content.protopic protein products, micron / MP Duration 72 79 84 92 0.183 0.022 0.247 0.030