Bacteria are some of the most ancient creatures to still exist today. You probably know them as a type of germ, but they can do much more than cause disease! They are responsible for carbon and nitrogen fixation, two processes which are crucial to all lifeforms. They live in some of the hottest (and coldest) places on Earth. They ferment foods and liquids to make things like pickles and beer. These are just a few examples of neat ‘powers’ bacteria have that humans don’t. Remember, not all bacteria are bad!
Cause disease – Escherichia coli
While it is true that humans can spread disease, they aren’t the ones truly causing the illness – instead, a microorganism is typically to blame! Many bacteria can cause disease, Escherichia coli being a well-known example which infects various organ systems. In fact, while E. coli are notably responsible for a diarrheal illness, infection with the species can also lead to respiratory and urinary tract illnesses. Additionally, the bacterium is one of the leading causes of meningitis in children. It is also worth noting, however, that E. coli is normally found in the lower gastrointestinal tract (the intestines) of healthy animals and humans and only causes disease when found outside that area.
Live in hot springs – Thermus aquaticus
Bacteria are an extremely diverse set of organisms, many of which can only live under very specific circumstances. Some bacteria, for instance, cannot grow in the presence of oxygen, while others can withstand great temperatures. Those bacteria that can tolerate high heat are known as thermophiles. Indeed, Thermus aquaticus is one such bacterial species that can live at temperatures of up to 176℉. This property of T. aquaticus makes it very practical in molecular biology applications, which often make use of a heat-sensitive DNA replication technology called polymerase chain reaction (PCR). Prior to the 1966 discovery of T. aquaticus in Yellowstone National Park, DNA replication processes were inefficient and slow.
Survive immense amounts of radiation – Deinococcus radiodurans
Going beyond resistance to a single extreme condition is the unique, hardy polyextremophile Deinococcus radiodurans, which holds the Guinness World Record for the most radiation-resistant lifeform. These tough bacteria have been discovered in irradiated tin cans as well as in the Sahara. Given a species name meaning “radiation enduring”, it is no wonder that D. radiodurans can survive doses of radiation larger than those which naturally occur on Earth. In fact, the bacteria have been shown to recover following exposure to 7 kGy of ionizing radiation – the equivalent of about seventy million chest X-rays. This extraordinary ability probably evolved because of the effects of other, non-radioactive extreme phenomena that damage DNA such as dryness in drought conditions.
Use oil for energy – Alcanivorax borkumensis
Although I’m not jealous of a living thing which eats petroleum all day, such a thing does sound quite useful. Found throughout the sea but dominating the microbiota of oil-polluted areas, Alcanivorax borkumensis is exactly that thing: an organism that can break down many types of alkanes (the chemistry word for carbon- and hydrogen-containing compounds such as gasoline). Besides metabolizing hydrocarbons, this bacterial species also forms an emulsifying biofilm, reducing surface tension and further heightening the solubility of the oil molecules in water.
Glow in the dark – Vibrio harveyi
This close relative of the aquatic microorganism that causes cholera (Vibrio cholerae) also causes a gastrointestinal illness, but only in marine animals. On a way cooler note, colonies of Vibrio harveyi can do what their human pathogen cousin cannot – orchestrate themselves to produce a neat glow. Coming back to what the bacteria have in common, both bioluminescence and virulence genes are expressed in response to a cell-to-cell chemical signaling process called quorum sensing. Fluctuating with changes in cell density, quorum sensing coordinates actions between bacteria of the same or different species, depending on the particular gene. The light of V. harveyi is so bright that it causes shrimp suffering from a commonly deadly infection that the bacteria causes, aptly known as luminous vibriosis, to glow. Much larger populations of the bacteria are thought to be responsible for the “glowing seas effect,” a phenomenon when the ocean appears to emit a light that has been observed from space.
Detect magnetic fields – Magnetospirillum magneticum
While humans have to use a compass to differentiate between north and south in an unfamiliar area, some water-dwelling bacteria have specialized compartments called magnetosomes which allow them to detect magnetic fields and orient themselves appropriately. All bacteria with magnetosomes, called magnetotactic bacteria, also have flagella, which are structures that help them move. Magnetosomes contain magnetic crystals which bacteria use to identify varying oxygen concentrations; the bacteria move in response to the oxygen level detected in order to place themselves in an ideal environment. This means of detecting magnetic fields is disparate from the way by which animals detect them, so even dead bacterial cells will orient themselves. Magnetospirillum magneticum was the first discovered magnetotactic bacterium.