US 12,441,976 B2
Process for reducing the activity of microbial contamination in a yeast medium
Jeffery R. Broadbent, Amalga, UT (US); James L. Steele, Lebanon, NH (US); Brooks Henningsen, Salisbury, NH (US); Ekkarat Phrommao, Lebanon, NH (US); and Fernanda Cristina Firmino, Atlanta, GA (US)
Assigned to DANSTAR FERMENT AG, Zug (CH)
Filed by Lallemand Hungary Liquidity Management LLC, Budapest (HU)
Filed on Jul. 9, 2021, as Appl. No. 17/372,372.
Claims priority of provisional application 63/050,593, filed on Jul. 10, 2020.
Prior Publication US 2022/0010265 A1, Jan. 13, 2022
Int. Cl. C12N 1/16 (2006.01); C12R 1/225 (2006.01); C12R 1/865 (2006.01)
CPC C12N 1/16 (2013.01) [C12N 2500/30 (2013.01); C12N 2500/72 (2013.01); C12N 2500/74 (2013.01); C12R 2001/225 (2021.05); C12R 2001/865 (2021.05)] 26 Claims
 
1. A process for making a medium for a yeast, the process comprising:
(i) adjusting the pH of a raw medium with a strong acid to provide a first acidified medium having a pH below 4.5;
(ii) maintaining the first acidified medium at the adjusted pH for a period of time to provide a second acidified medium, wherein the period of time is at least 10 minutes; and
(iii) adjusting the pH of the second acidified medium with a base to provide the medium for the yeast having a pH above 4.5;
wherein
the process comprises adding an antimicrobial composition to the:
raw medium prior to or during step (i), and/or
acidified medium prior to or during step (ii);
wherein the antimicrobial composition comprises at least one weak acid, optionally, in combination with an acid stable bacteriocin and/or an antibiotic;
wherein step (i) comprises adjusting the pH of the raw medium below or equal to the pKa of the at least one weak acid of the antimicrobial composition; and
wherein step (ii) comprises maintaining the first acidified medium so as to decrease the contaminating microbial activity in the second acidified medium, when compared to a corresponding control medium not previously treated with the antimicrobial composition; and
wherein the raw medium comprises a fermentable material.