Chapter
5. The hidden biodiversity of microbes

5. The hidden biodiversity of microbes

The more we study the biodiversity of microbes, the more diversity we find and the more important it turns out to be. Microbes are difficult to study because they are invisible to the naked eye, but in recent years technological advances have revolutionised our understanding of microbes.

In the video we learned about the current state of knowledge about the diversity and important of microbes, new scientific methods, and the way microbes have been studied in Finnish nature.

The clip comes with subtitles in English. Just click play, select the gear icon on the lower right and select subtitles in English.

Read more about the biodiversity of microbes

Read more about Finnish scientific studies that shed light on the diversity of microbes in nature and its importance for humans.

  1. Diversity of viruses of Plantago in Åland islands.
    Original articleYle news article on the research (in Finnish)
    Susi H, Filloux D, Frilander MJ, Roumagnac P, Laine A. 2019. Diverse and variable virus communities in wild plant populations revealed by metagenomic tools. PeerJ 7:e6140 DOI:10.7717/peerj.6140

  2. Skin microbiota differs in children and teenagers between rural and urban environments.
    Original articleYle news article on the research (in Finnish)
    Lehtimäki, J., ym. 2017. Patterns in the skin microbiota differ in children and teenagers between rural and urban environments. Scientific Reports 7, Article number: 45651. DOI:10.1038/srep45651

Find out

Micorbes are difficult to see, and the most modern methods that scientists use to see them are so far only available to professional laboratories. But good oll petri dish culturing is still a good way to see microbes. To see the how microbe communities work, we can use computer simulations.

How fast do bacteria reproduce

The speed at which bacteria reproduce is due to their ability to divide. One cell divides into two, which divide into four and so on. This is called exponential growth. Imagine that a single bacterial cell is transferred from your phone screen to your finger, and from there to your nose. The nose is a perfect environment. Now the cell divides every 20 minutes. How many bacteria are there in your nose 24 hours later? How long does it take to get to a million bacteria?

Culture microbes in a petri dish

You will need petri dishes, which schools can purchase in bulk. The petri dish contains a solid growth medium that is suitable for a lot of different bacteria. In every experiment you will add something to the dish, then replace the lid and incubate the dishes upside down for a few days at +37 degrees Celsius (or as close to that as possible).

Plant disease herbarium

Put together a herbarium (a collection of plant samples), focusing on plants that are showing symptoms of plant diseases. When collecting samples, keep a log of the places and dates of collection. Examples of plant disease symptoms can be found e.g. here and here. Look up some photos before you go out collecting, so you have some idea of what you are looking for.

Typical symptoms of fungus infections in plants are growths on the plant surface, colour changes and deformities. Recognising plant diseases is not easy because deformities and colour changes can also be caused by a lack of nutrients – don’t worry if some of those end up in you collection, too. Don’t be afraid to collect samples that you don’t recognize – maybe someone else will identify them later!

What did you notice in making the collection? Did you find diseases in particular places? Was there a difference between different diseases – are some diseases on almost every plant and others only here and there?