Bacterium

A method for manufacturing a lactic acid bacterium that generates higher shear stress and/or gel stiffness than its mother strain when the bacterium is used for fermenting milk, comprising:

• (a) providing a lactic acid bacterial strain as the mother strain;
• (b) exposing the lactic acid bacterial strain to a bacteriophage which is able to lyse the mother strain;
• (c) optionally, before during, or after step (b), introducing into the lactic acid bacterial strain a mutation in the galK gene or a galK regulatory sequence;
• and
• (d) subsequently isolating the bacterial strain, wherein the isolated strain (i) is resistant against more phages than the mother strain and (ii) has a mutation in a galK gene or a galK regulatory sequence relative to the mother strain.