Growing soil microbes
In this activity, students investigate microbial presence in soil by building a habitat suitable for their growth.
Known as Winogradsky columns, mud, newspaper and eggs create a variety of habitats that promote the growth of soil bacteria and algae. With time, sulfur and oxygen gradients form and a diversity of microorganisms grow in response to these conditions, often forming distinctive colour bands.
Growing soil microbes in Winogradsky columns
The image on the left is soil on the first day, the image in the middle is two weeks later. The image on the right is a column that has been growing for several years.
The conditions within a Winogradsky column allow microorganisms to grow into visible and colourful colonies.
By the end of this activity, students should be able to:
demonstrate that the soil is home to many microorganisms.
explain that microbes grow in response to different needs such as light, oxygen, no oxygen and various energy sources.
Download the Word file for:
introduction/background notes
what you need
what to do
discussion questions
student handout.
