Question

IlI You work in a food fermentation factory, and you have been given three different bacteria strains (their metabolic chart is available below).Your task is to ferment milk and produce yogurt. Answer the following questions. Strain 1 Strain 2 Strain 3 Col NAC Ethanal PLACTARE 1. What is the fermentation group does each strain belong to? 2. Which strain would you use to make yogurt? and why? 3. Would you use any of these strains to ferment dough and make bread? and why?

Answer 1

1. Since strain 1 produces lactate as the final product of fermentation, it is a lactic acid fermenter bacteria. Strain 2 is both a lactic acid fermenter and alcoholic fermenter. Strain 3 is a lactic acid, ethanol and acetic acid fermenter.

2. Strain 1 can be used for making yogurt as this bacteria produces lactic acid (or lactate), which acts on the milk proteins and causes them to denature and coagulate, giving it a thick texture similar to that of curd.

3.Strain 3 can be used making bread as it produces carbon dioxide as a by product of its fermentation. This CO₂ forms bubbles that gives fluffiness to the dough and causing it to expand.