Students discover that not all bacteria is harmful.
Year 8 pupils have been studying a unit on disease and microbes in their Biology classes. They have looked at types of bacterial diseases such as cholera and typhoid as well as viral diseases like influenza and small pox. As part of the topic, Dr Ryalls and Dr Parker have also impressed upon them that many bacteria are harmless and even beneficial for good health.
In a hands-on lesson, Dr Ryalls took his pupils through the process of making yoghurt with live bacteria. He also showed the girls that imitation meat (quorn) is a micro protein derived from fungi and they saw how the rind of a blue cheese like Stilton is injected with mould spores.
Focusing on yeast, both teachers led their classes through the various steps of making bread, Dr Ryalls with a breadmaker and Dr Parker by hand. What they both had in common was their desire to show the girls how a useful microbe works. While mixing the ingredients together, the pupils learnt that when yeast is combined with a sugar or starch it respires and releases carbon dioxide. The gas is trapped in the dough in the form of little bubbles which then make the dough rise.