Autotrophic organisms obtain their energy from the sun or from chemical compounds. Most of the earth is covered with such autotrophic organisms. After all, plants need only the sun for their energy. But did you know that there are also autotrophic microbes?
Autotrophic organisms obtain their energy from the sun or from chemical compounds. Most of the earth is covered with such autotrophic organisms. After all, plants need only the sun for their energy. But did you know that there are also autotrophic microbes?
Different autotrophes
Autotrophic organisms can be roughly divided into two groups depending on what type of energy source they use. We call these groups photoautotrophs (living on energy from the sun) or chemoautotrophs (living on energy from chemical sources). Autotrophs use CO2 from the atmosphere as a building block to make complex organic compounds such as carbohydrates. Most of the autotrophic organisms are photoautotrophs, and this goes for microbes too. Micro-algae for instance, receive their energy from sunlight, as well as cyanobacteria.
Chemical talents
More organisms than just microbes can live from sunlight. But living on only pure chemical compounds is so hard that only microbes with exceptional talents can manage this. For example, bacteria that live around hot water sources in the deep sea. There they manage to survive under the harshest circumstances by feeding on sulfuric and ferric compounds. Most chemoautotrophs are therefore also extremophiles.
Where do you get your energy?
But what if you can’t get your energy from chemical sources or the sun? Then you are living on second-hand matter, which has been created by autotrophs. We call these organisms that live on existing organic matter heterotrophic. A lot of microbes are heterotrophs, and we humans are as well. We might enjoy a good sunbath, but unfortunately, we cannot live from it.
Are you curious how bacteria behave like autotrophic algae? Visit Micropia and take a look at the exhibit ‘Small life, big impact’ in Micropia.