Bacteria

The microorganisms have adapted to thrive in some of the harshest conditions on Earth. Despite their single-cell structure, bacteria possess unique physiological and genetic traits that allow them to survive in extreme temperatures, high salinity, acidic conditions, and even radioactive environments.

Introduction of Bacteria

Bacteria are singular-celled and microscopic, which are found everywhere in the world, including in the seas, oceans, and even in the human body. They are some of the oldest known species of life and are unique in their versatility to both friendly and unfriendly environments. Bacteria are involved in a vast number of processes within ecosystems and are involved in breaking down waste, helping animals digest food, and are used in the biochemical process of fermentation. Thus, many people think that bacteria are dangerous; it is necessary to realize that the majority of them are innocent or even useful and play a significant role in maintaining life and the equilibrium of the existing life environment.

Structure of bacteria

Cell wall

The cell wall of many bacteria is peptidoglycan; this is important for the bacteria, for it helps them maintain shape and serves as a barrier to the bursting of the bacterial cell. In Gm-positive bacteria, the layer of peptidoglycan is very thick, while in Gm-negative bacteria it is comparatively thin.

Cell membrane

This determines the passage of materials into or out of a cell. And it is something to consider that the bacterial membrane is phospholipids and proteins.

Semi-fluid substances of water, enzymes, nutrients, and other substances or materials in the cell. This is where most of cellular metabolism takes place.

Ribosomes

These are cellular organelles and sites of protein synthesis. Bacterial ribosomes differ in structure from that of the eukaryotic ribosomes.

Chromosomes

Almost all bacteria have a single icosahedral nucleoid containing one (or more) circular DNA chromosome(s) or multiple small circular entities termed plasmids.

Appendages

If bacteria were noted to also have surface organelles, such as flagella for motility and pili (or fimbria) for adhesion.

Inclusion bodies

It is known that some bacterial cells also store carbon and energy products in the form of polymers, such as glycogen.

Bacterially, the two types of bacteria differ in their outer periphery to the cell envelope, which consists of peptidoglycan. However, the components of internal structures such as the cytoplasmic region, the ribosomal region, the nucleoid with the genetic material, and the cell membrane are shared by both.

Important Adaptations of Bacteria to Extreme Environmental Conditions

Thermophiles

Like Thermus aquaticus, bacteria exist where temperatures are above 45 °C. They are normally located in hot springs and hydrothermal vents. Their enzymes, especially DNA polymerases, are heat stable and play a significant role in biochemical technology, such as PCR (polymerase chain reaction).

Halophile

Extremophiles inhabiting salt marshes, deserts, plains, or lakes balance their intracellular osmotic environment by synthesizing or accumulating compatible solutes such as potassium ions.

Acidophiles

Living on extreme acid with a pH between 1 and existing in extremely acidic environments like hot springs abundant in sulfuric acid and mine drainage, the cell membrane of acidophilic bacteria does not permit an influx of protons into the cell, hence they survive.

Radioresistant Bacteria

An outstanding example of such a bacterium is Deinococcus radiodurans, which is capable of surviving in radiation conditions three times higher than fatal for a human being. For instance, it has relatively sound DNA repair capabilities, allowing it to rapidly repair any harm caused by irradiation.

Psychrophiles

Bacteria thrive at temperatures below zero degrees; psychrophilic bacteria can be obtained from Arctic and Antarctic ice. They are bilayers composed of phospholipids with a high content of unsaturated fatty acids that make their membrane flexible to support their functions even in freezing conditions.