“Bacteria” is a broad term for a domain of prokaryotic microorganisms. There are more known species of bacteria than any other domain of organisms on Earth, and exist in nearly every habitat, from radioactive to frigid environments. While typically only a few micrometers in length, bacteria are responsible for a vast percentage of natural processes, including decomposition, digestion, and regulation of the nutrient cycle in soils.
As mentioned previously, bacteria are prokaryotic organisms, meaning they lack a nucleus and generally all other distinct membrane encased organelles. While generally measuring between 0.5 and 5.0 micrometers, bacteria exist in many different shapes and sizes, such as rods, spheres, and spirals. This is called the “morphology” of the bacteria. Most species are either rod shaped, called bacilli, or spherical, called cocci. They reproduce through a process called binary fission, which is essentially a period of brief growth following by a divide. In this way, most bacteria can replicate extremely quickly, making some bacterial infections very difficult to treat.
While bacteria provide many important functions that help regulate natural processes, there are also many known bacteria that cause severe human infection. Some of these include types of pneumonia, leprosy, some sexually transmitted diseases, and even the bubonic plague. Another well-known bacterium is Escherichia coli, more commonly known simply as E. coli. This particular bacterium, like many others, is commonly found in humans without causing significant problems to hosts’ health. However, certain strains have been known to cause very severe food poisoning and other more life threatening infections.
The study of bacteria is known as bacteriology, a sub discipline of microbiology. Because these organisms are responsible for so many processes in our own bodies, as well as nature as a whole, understanding how they function is of incredible significance. With modern advancements being made every day in research technology such as microscopes and antibiotic medicines, scientists are able to better understand useful bacteria, and fight those species that cause infection in humans.