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Helpful microorganisms

Here are some examples of useful microorganisms.

  • When bread is made, a microorganisms called yeast is added to the dough to make the bread rise.

    Iluustration of a loaf of bread with the micro-organisms highlighted
  • Yoghurt is made by boiling milk and adding special bacteria to it. The bacteria turn the sugar in the milk into acid. The acid makes the milk go thick and stops any harmful bacteria growing.
    Illustration of a carton of yoghurt highlighting the micro-organisms

  • Inside a pile of dead leaves are millions of tiny bacteria. These bacteria feed on the leaves and break them down into nutrients. The nutrients go back into the soil where they can be used by plants.
    Illustration of a leaf highlighting the micro-organisms

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