Bacterial metabolism is the process which bacteria use to stay alive. Metabolic processes in bacteria are quite diverse and extremely fascinating, at least for people who are interested in this sort of thing. Bacteria have evolved an astounding number of ways to access energy available in the natural environment so that they can use it to stay alive and perform a variety of functions. Bacterial metabolism is also harnessed by other organisms; humans, for example, rely on bacteria in their gut to break down food into components which their bodies can access.
One aspect of bacterial metabolism involves the collection of energy. One of the processes available to bacteria is familiar to humans: respiration. However, unlike humans, bacteria can use gases other than oxygen in their respiration processes, and some bacteria are even capable of surviving in anaerobic environments as well as environments which contain air. This is a rather remarkable adaptation which allows the bacteria to survive in harsh environments as circumstances change.
Many bacteria are heterotrophs, using organic materials for energy just like humans do. The organisms can access the molecules inside the materials in a variety of ways. One technique they use is fermentation, in which materials are broken down into usable components. Some bacteria can also photosynthesize, using the sun for energy as long as they have access to nutrients, and others are capable of surviving on inorganic materials. Known as lithotrophs or autotrophs, these bacteria can survive in extremely harsh environments.
The utilization of energy inside a bacterium can also vary, depending on the species. Bacteria use energy for movement, if they are motile, and for a variety of other tasks. Some bacteria have evolved interesting ways to use the energy they can access to maintain internal functions.
Bacterial metabolism allows bacteria to stay alive so that they can reproduce, ensuring that the species survives through at least one more generation. The diversity of processes used by bacteria to metabolize illustrates the wide range of environments in which they can survive. Bacteria are capable of using almost anything for energy, as long as they happen to be the right species in the right environment. Some, known as extremophiles, like environments so harsh that people originally thought no living organisms could survive in them, such as hot springs and the workings of nuclear power plants.
In addition to being of intrinsic interest, bacterial metabolism has a number of applications. Some fermented foods are made with bacteria, making it important to know which bacteria are involved and how they work. Bacterial metabolism is also important to animal metabolism, with the bacteria playing a role in the metabolic processes of the larger organism by breaking ingested food down into components which the body can metabolize.