KS3: Useful Microbes In this lesson, students learn that microbes can be useful, experimenting with Lactobacillus and Streptococcus to make their own yoghurt. Scroll down for more information and to download resources. Download the complete lesson Understand that some microbes can be put to good use Understand that we need bacterial colonisation to live a healthy life Understand that we need to protect our normal microbial flora Bacteria are single-celled organisms and although some of these cause illness...