Bacteria Biology

Question

Hello!

I have a question.

I know that an organism can be either photoautotrophic, chemoautotrophic, photoheterotrophic and chemoheterotrophic.

What I want to know is that are there types bacteria within each of these groups?

Thanks in advance!

Answer 1

Hey Maya,

Good Question!

The short answer: Kind of. What you have listed are four different ways to classify how bacteria can obtain energy, via photosynthesis or chemosynthesis, depending on where the carbon required for these pathways is obtained (auto from within, hetero from the environment). There are however different pathways to obtain energy, such as symbiosis (mutualism, parasitism, commensalism). The four that you have listed can be broken down further into groups such as Obligate and Facultative. Obligate means that they require a certain characteristic of the environment, such as the presence or absence of Oxygen, inorder for photosynthesis, chemosynthesis, or respiration/fermentation to occur. Facultative means that they can operate in either condition, presence or absence. Most commonly these are used to describe the bacteria that gain energy in the presence of oxygen (Aerobes) vs those that don't (Anaerobes). For example you could have a photoautotrophic obligate aerobe, meaning the source of carbon for photosynthesis comes from the bacteria's own carbon, and oxygen is needed in the environment for the bacteria to produce energy and survive. These "groups" are more so descriptions of bacteria, and not exclusionary. There are many types of bacteria, that operate in many different conditions, and there is generally multiple descriptive words we can use to describe and classify that "group" or species of bacteria. Whether you view view being photoautotrophic as a subset of the different anarobic/aerobic bacteria, or you view anarobic/aerobic bacteria as being a subset of photosynthetic/chemotrophic bacteria is completely up to how you want to categorize the information. More accurately though, these are just words to describe different features of bacteria, and are not exclusionary.