SU721488A1 - Streptococcus diacetilactis aroma-producing lactic streptococci strain employed in bacterial preparate for cheeses with low second heating temperature - Google Patents

Description

Noah sticks, active acid formation in milk.

The strain streptococcus .aceti otis 124, isolated from the self-sour cream and selected. It is stored in the collection of the production laboratory of biopreparations of the NPO Uglich and the Museum of Culture of the Institute of Scientific Research Institute of Genetics and CMPM B-1690.

Morphologists, Oval forked cells, arranged in two and short chains, cell diameter 0.60, 9 microns, Gram-positive,

Cultural and biochemical properties. Organic environments. On hydrolyzed milk agar, the strain forms whitish, drop-like colonies, with a smooth edge, their diameter is 48 hours of cultivation at 0.81 mm;

Ferment milk with minimal seeding after 11-14 h, forms a smooth, dense clot without peptonization. The optimal growth temperature is 30 ° C, it grows at 9 and 40 ° C, at 45 ° C - no growth. Extreme acidity at 9 and 30 ° C - 114 ° T. Well developed in milk at combined temperature conditions created when cheese is produced and ripening at. It has a high acid production energy in milk at 45 ° after 4 hours and milk with rennet. 54t

It has lipolytic activity - lipolysis grains 4.5-5 mm, moderate gas generation - 4.2 cm of Eingorn device, antagonism to E. coli - growth zone of 3.5-4 m, does not form bitterness in milk with rennet fatty acids 1.7 ml of 0.1 N NaOH and diacetyl - 0.297 mg%.

It grows in hydrolyzed broth with the addition of 2-5% of common salt, does not grow at 6.5%, grows in hydrolyzed. broth at pH 9.2 and does not grow at pH 9.6, Restores and rolls up the litmus milk at 30 and does not change it at, Withstands heating for 15 minutes and does not stand for 30 minutes.

Absorbs glucose, lactose, galactose, levulose, mannitol, maltose, sucrose, arabinose, sorbitol, starch glycerin; poorly absorbs inulin and raffinose.

The strain was introduced into the composition of the bacterial preparation and tested during the development of Kostroma cheese on. Nagoryevsky Cheese Factory, Yaroslavl region.

For the production of a bacterial preparation used in the production of cheeses with a low temperature of the second heating, take cultures VHgerHossossiz tacxis648, 791 ,, 504

Streptococ us creriSbris Gd, Streptococcus; .eac.is 124 with high energy of acid formation, streptococcus caiacetitoctis 1642 with weak energy of acid formation and Streptococcus parocitrovorua 1895 and prepare inoculum of each species separately (in sterile milk),

In order to accumulate the bacterial mass, a nutrient medium is prepared, for which skimmed milk powder is restored (at the rate of 30 g per 1 liter of tap water with a temperature of 40-45 ° C) for 30-60 minutes and the hydrolysis of the milk proteins with the enzyme Protomesterin G10x, taken at the rate of 20 thousand, units, for 30 g of powdered milk in 1 l. - Hydrolysis temperature 55-57 ° C, duration 2 hours. After hydrolysis is terminated, sodium citrate, corn extract, lactose (glucose) 1% each and manganese sulfate 160 mg / l are added to the medium, the pH is adjusted to 7.27, 5 and sterilized at 1 amu 1520 min (in tanks), when working in fermenters - for 30 min., The medium cooled to 30 ° C is inoculated in an amount of 3.4% in the following ratio: mixture of strains str. eoctis - 0.2%, Str. cremorts 1, 2%,. Str. diacetitacXi, with high acid-forming energy — 0.6%, svr.diacetWactis, with weak acid-generating energy — 0.2%,. paracitrovprus - 1.2% and cultivated for 9-12 hours,

During cultivation, accumulated lactic acid is neutralized (periodically or continuously).

At the end of the cultivation, the mixture is cooled and centrifuged. The isolated bacterial mass is combined with a protective medium (10% aqueous sugar solution and 5% sodium citrate) in a 1: 1 ratio, then frozen and dried by sublimation,

The dry bacterial preparation is pulverized, monitored and packaged in vials in portions of 0.5-1 g,

At the cheese-making factories, a production ferment is prepared from the bacterial preparation by a direct method (mowing 14-18 h), the consumption of the preparation per 300 liters of milk. The leaven obtained in this way is used in the production of cheese in a dose of usually 0.7-1.5%.

Claims (1)

1. USSR author's certificate 470532, class, C 12 K 3/00, 1973 (prototype),