Streptococcus thermophilus strains

Patent metadata

Field	Value
Publication number	US-10368559-B2
Application number	US-201414905125-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Jul 17, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

The present invention relates to Streptococcus thermophilus strains, usable as starter cultures, able to provide both satisfactory rheological and organoleptic properties, and satisfactory shelf life to the media into which they are incorporated. In particular, these strains are also bacteriophage-resistant, thereby minimizing bacteriophage infection. The invention also provides a composition comprising one of these Streptococcus thermophilus strains, and feed or food products obtained with these strains.

First claim

The invention claimed is:

1. A composition comprising a Streptococcus thermophilus strain and a food acceptable component, wherein:
the food acceptable component is selected from cryoprotective agents and boosters;
the Streptococcus thermophilus strain exhibits milk acidification kinetics characterized as follows:
(1) an average speed of acidification between pH 6.00 and pH 5.30 which is at least 70×10 −4 UpH/min, and
(2) an average speed of acidification between pH 5.30 and pH 5.00 which is no greater than 22×10 −4 UpH/min; and

the average speeds of acidification of (1) and (2) are measured under the following conditions:
ultra high-temperature pasteurized cow-milk milk having a fat content of fat 1.5% (w/w) is supplemented with 3% (w/w) skimmed milk powder to form a mixture at a temperature of from 20 to 25° C.;
after the powder dissolves, the mixture is heated to 90° C. over a period of no greater than 35 minutes;
the mixture is maintained at 90° C. for 10 minutes and then cooled to 35° C.-45° C. over a period of no greater than 45 minutes;
1 g/100 L of sodium formate is added to the mixture;
the mixture is inoculated with the Streptococcus thermophilus strain, wherein:
the Streptococcus thermophilus strain is in a preserved form at −80° C. in a milk-based medium, and
the inoculation rate is 1×10 6 CFU/ml of the milk-base medium; and

the inoculated mixture is incubated at a temperature of 43° C. (+/−1° C.), which is kept constant in a water bath, while measuring change in pH every 5 minutes for 24 hours.

2. The composition of claim 1 , wherein the Streptococcus thermophilus strain is selected from the group consisting of:
(1) the DSM 27029 strain, deposited under the Budapest Treaty on Mar. 21, 2013 in the name of Danisco Deutschland GmbH at the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, GmbH;
(2) the DSM 27030 strain, deposited under the Budapest Treaty on Mar. 21, 2013 in the name of Danisco Deutschland GmbH at the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, GmbH;
(3) the DSM 27031 strain, deposited under the Budapest Treaty on Mar. 21, 2013 in the name of Danisco Deutschland GmbH at the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, GmbH; and
(4) a mutant strain having all of the identifying characteristics of the DSM 27029 strain, of the DSM 27030 strain, or of the DSM 27031 strain.

3. A composition comprising a Streptococcus thermophilus strain, wherein:
the composition is in a liquid, frozen or dried-powder form;
the Streptococcus thermophilus strain exhibits milk acidification kinetics characterized as follows:
(1) an average speed of acidification between pH 6.00 and pH 5.30 which is at least 70×10 −4 UpH/min, and
(2) an average speed of acidification between pH 5.30 and pH 5.00 which is no greater than 22×10 −4 UpH/min; and

the average speeds of acidification of (1) and (2) are measured under the following conditions:
ultra high-temperature pasteurized cow-milk milk having a fat content of fat 1.5% (w/w) is supplemented with 3% (w/w) skimmed milk powder to form a mixture at a temperature of from 20 to 25° C.;
after the powder dissolves, the mixture is heated to 90° C. over a period of no greater than 35 minutes;
the mixture is maintained at 90° C. for 10 minutes and then cooled to 35° C.-45° C. over a period of no greater than 45 minutes;
1 g/100 L of sodium formate is added to the mixture;
the mixture is inoculated with the Streptococcus thermophilus strain, wherein:
the Streptococcus thermophilus strain is in a preserved form at −80° C. in a milk-based medium, and
the inoculation rate is 1×10 6 CFU/ml of the milk-base medium; and

the inoculated mixture is incubated at a temperature of 43° C. (+/−1° C.), which is kept constant in a water bath, while measuring change in pH every 5 minutes for 24 hours.

4. The composition of claim 3 , wherein the composition is in a frozen form.

5. The composition of claim 3 , wherein the composition is in a freeze-dried powder form.

6. The composition of claim 3 , wherein the Streptococcus thermophilus strain is selected from the group consisting of:
(1) the DSM 27029 strain, deposited under the Budapest Treaty on Mar. 21, 2013 in the name of Danisco Deutschland GmbH at the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, GmbH;
(2) the DSM 27030 strain, deposited under the Budapest Treaty on Mar. 21, 2013 in the name of Danisco Deutschland GmbH at the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, GmbH;
(3) the DSM 27031 strain, deposited under the Budapest Treaty on Mar. 21, 2013 in the name of Danisco Deutschland GmbH at the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, GmbH; and
(4) a mutant strain having all of the identifying characteristics of the DSM 27029 strain, of the DSM 27030 strain, or of the DSM 27031 strain.

7. A method for preparing a food or a feed product comprising:
putting into contact a substrate with a culture of a Streptococcus thermophilus strain; and
obtaining the product, wherein:
the substrate comprises pasteurized milk;
the Streptococcus thermophilus strain exhibits milk acidification kinetics characterized as follows:
(1) an average speed of acidification between pH 6.00 and pH 5.30 which is at least 70×10 −4 UpH/min, and
(2) an average speed of acidification between pH 5.30 and pH 5.00 which is no greater than 22×10 −4 UpH/min; and
the average speeds of acidification of (1) and (2) are measured under the following conditions:
ultra high-temperature pasteurized cow-milk milk having a fat content of fat 1.5% (w/w) is supplemented with 3% (w/w) skimmed milk powder to form a mixture at a temperature of from 20 to 25° C.;
after the powder dissolves, the mixture is heated to 90° C. over a period of no greater than 35 minutes;
the mixture is maintained at 90° C. for 10 minutes and then cooled to 35° C.-45° C. over a period of no greater than 45 minutes;
1 g/100 L of sodium formate is added to the mixture;
the mixture is inoculated with the Streptococcus thermophilus strain, wherein:
the Streptococcus thermophilus strain is in a preserved form at −80° C. in a milk-based medium, and
the inoculation rate is 1×10 6 CFU/ml of the milk-base medium; and

the inoculated mixture is incubated at a temperature of 43° C. (+/−1° C.), which is kept constant in a water bath, while measuring change in pH every 5 minutes for 24 hours.

8. The method according to claim 7 , wherein the milk acidification kinetics of the strain are characterized by a ratio of the (1) average speed of acidification between pH 5.30 and pH 5.00 to the (2) average speed of acidification between pH 6.00 and pH 5.30 being less than or equals 25%.

9. The method according to claim 8 , wherein the milk acidification kinetics of the Streptococcus thermophilus strain are characterized by a ratio of the (1) average speed of acidification between pH 5.30 and pH 5.00 to the (2) average speed of acidification between pH 6.00 and pH 5.30 being between 2 and 25%.

10. The method according to claim 7 , wherein the genome of the Streptococcus thermophilus strain comprises a) a CRISPR4 locus comprising or consisting of the sequence as defined in SEQ ID NO:3 orb) a CRISPR4 locus comprising part(s) of SEQ ID NO:3.

11. The method according to claim 7 , wherein the genome of the Streptococcus thermophilus strain comprises a) a CRISPR1 locus consisting of SEQ ID NO:19, orb) a CRISPR1 locus comprising SEQ ID NO:19 or comprising part(s) of SEQ ID NO:19, and optionally additional CRISPR1 [re

Assignees

• Dupont Nutrition Biosci Aps

Inventors

• Horvath Philippe
• Fremaux Christophe
• Fourcassie Pascal

Classifications

• A23C9/127

  using microorganisms of the genus lactobacteriaceae and other microorganisms or enzymes, e.g. kefir, koumiss (A23C9/13 takes precedence) · CPC title

• C12N1/20

  Bacteria; Culture media therefor · CPC title

• A23C21/02

  containing, or treated with, microorganisms or enzymes · CPC title

• A23C9/1238 Primary

  using specific L. bulgaricus or S. thermophilus microorganisms; using entrapped or encapsulated yoghurt bacteria; Physical or chemical treatment of L. bulgaricus or S. thermophilus cultures; Fermentation only with L. bulgaricus or only with S. thermophilus · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title