Bacteria are the minute living organisms, which are found abundantly on the planet earth. It is also recognised as one of the earliest forms of life, which existed on the earth. They were the very earliest organisms to evolve on this planet earth, i.e. it was over 2 billion years before eukaryotes appeared.
Bacteria are a giant group of minute, unicellular living organisms, which are also called microbes or microorganisms. These microscopic organisms are called prokaryotes as they lack a true nucleus and other cellular organelles.
The bacterium is the singular word for bacteria. The study of bacteria is known as bacteriology and it is a branch of microbiology. Bacteria were first observed by the Dutch microscopist Antonie van Leeuwenhoek in 1675.
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Characteristics Of Bacteria
Bacteria mainly comprises a simple cellular structure, including:
- Cell wall
These microorganisms are found everywhere, all around us and are found in communities of millions. The shape of bacteria varies with the types and the length of a complete bacteria measures only a few micrometres.
Other structural features of these prokaryotic microorganisms are:
- It lacks a membrane-bound nucleus.
- It has a circular shaped, single chromosome of DNA found within the cytoplasm.
- The nucleoid of a bacterial cell comprises the chromosome with its associated proteins and RNA.
- Every bacterial cell has its own plasmids, which are involved in replication, food digestion, etc.
- These plasmids are small, circular, double-stranded DNA Structure, which are naturally found in all bacterial cells.
- The mode of reproduction process in bacteria is both through sexual and asexual methods. Most bacteria rely on binary fission.
There are several different types of bacteria and the classification of Bacteria are mainly based on their
- Mode of Respiration – Aerobic or Anaerobic.
- Nutritional Patterns: Autotrophic or heterotrophic.
- Reproduction: Binary fission, conjugation, transduction and transformation.
- Shapes: Bacillus, Coccus, spirillum or spirochete and Vibrio.
- Cell wall composition: Gram-positive and Gram-negative.
Interesting Facts about Bacteria
Bacteria play a primary role in regulating biogeochemical systems.
These bacteria also protect our body from defending the invading pathogens.
The smell of rain is also caused by a certain group of gram-positive bacteria present in the soil.
Compared to the other human body parts, mouth and belly buttons have more than a thousand to millions of new species of bacteria.
Bacteria act as biocontrol agents and also act as cleaning and disinfectant agents.
These bacteria are both beneficial and harmful for humans, animals and also for plants.
Bacteria are present both outside the body and deep inside in our gut which helps indigestion.
Bacteria occur in different shapes and sizes – sphere, rod, spiral and spherical shaped.
There are many bacteria present in our gut which helps in digestion and protects our body from defending the invading pathogens.
Bacteria form a crucial part of the ecosystem, which takes part in activities like production of gases like oxygen, carbon dioxide and nitrogen and minerals like nitrogen, sulphur, etc.
There are various applications of bacteria, which includes food and beverage industries, the pharmaceutical industry, in the production of biofuel, biopesticides and so on.
Also Refer: Interesting Facts about Biofuels
A human body has 10 times more bacterial cells than human cells. These bacteria may either be a good bacteria or a pathogen- disease-causing bacteria like various bacterial infections and other fatal diseases.
Similar to other animals and birds, bacteria also communicate with each other by sending electrical signals. In this way, a colony of bacterial cells communicates and works together.
Actinomycetes are Gram-positive, mycelial, soil bacteria, which are more beneficial to humans. They are a great source of antibiotics and are also used in the production of a wide variety of chemotherapeutics, fungicides, herbicides and other industrially relevant compounds.
According to WHO and other medical records, one-third of the total world’s population has been infected with a dangerous and highly contagious bacterial disease called TB-Tuberculosis.
Also Refer: Common Bacterial Diseases in Humans
This article concludes an introduction to bacteria and its amazing facts. To know more about bacteria, types of bacteria, their beneficial and harmful effects on human beings and other related topics, keep visiting our website at BYJU’S Biology.