Low post-acidifying lactic acid bacteria

Patent metadata

Field	Value
Publication number	US-9480270-B2
Application number	US-30486807-A
Country	US
Kind code	B2
Filing date	Jun 22, 2007
Priority date	Jun 23, 2006
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

The present invention relates to lactic acid bacteria that have low or reduced post-acidification properties, and to a method for providing such bacteria. Also, the invention relates to the use of such bacteria for manufacturing of fermented dairy products, and to dairy products containing the bacteria.

First claim

The invention claimed is:

1. A method for producing from a mother strain a mutant Lactobacillus delbrueckii subsp. bulgaricus strain that produces less acid compared to the mother strain when present in a fermented dairy product, comprising:
(a) treating a culture comprising the mother strain with a mutagen, wherein the mother strain is selected from the group consisting of CHCC3984, CHCC3606, CHCC5713, and mutants thereof that (i) produce a dairy product that has a viscosity of at least 25 Pa in 9.5% milk without the addition of a thickening agent and (ii) decrease the pH of a dairy product more than 0.20 pH units after 7 days of storage at 8° C.; and then
(b) screening the treated culture for a mutant strain that (i) produces a dairy product that has a viscosity of at least 25 Pa in 9.5% milk without the addition of a thickening agent and (ii) decreases the pH of a dairy product less than 0.20 pH units after 7 days of storage at 8° C.

2. The method of claim 1 , wherein the mutagen is ethyl methane sulfonate, nitrous acid, methyl methane sulfonate, nitrosoguanidine, ICR-70 acridine mustard, or radiation.

3. The method of claim 2 , wherein the radiation is X-radiation or UV radiation.

4. A mutant strain of Lactobacillus delbrueckii subsp. bulgaricus produced by the method of claim 1 .

5. The strain of claim 4 , wherein the strain decreases the pH of a dairy product less than 0.30 pH units after 14 days of storage at 8° C.

6. The strain of claim 4 , wherein the strain produces a dairy product that has a pH in the range of 4.25 to 4.55 after 14 days of storage at 8° C.

Assignees

• Jensen Niels Bang Siemsen
• Johansen Annette Helle
• Chr Hansen As

Inventors

• Jensen Niels Bang Siemsen
• Johansen Annette Helle

Classifications

• 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

• C12N15/01

  Preparation of mutants without inserting foreign genetic material therein; Screening processes therefor · CPC title

• C12R1/225

  Chemistry & Metallurgy · mapped topic

• A23C11/106

  Addition of, or treatment with, microorganisms (A23C20/025 takes precedence) · CPC title

• A23Y2220/15

  Human Necessities · mapped topic