Microbes and Yoghurt production

Microbes and Yoghurt production

Select the correct answers from the drop-down options.

In making yoghurt, what bacterial waste product converts milk into the semi-solid yoghurt?
Why must milk be sterilised before adding the lactobacillus bacteria?
Why must yoghurt be kept cool in the fridge once bought?
What is the name of the sugar in milk that the bacteria break down?
What is the name of the soluble protein in the milk?