July 17, 2024
Medical Science

What is Bacteria?


1. Overview:

Small, single-celled organisms are known as bacteria (microbes). These microbes exist in nearly every place on Earth and are essential to the health of the planet’s ecosystems. Some species of bacteria endure situations of high pressure and temperature. In fact, it’s believed that microbe cells make up a larger portion of the human body than human cells. The majority of microorganisms in the body are benign, and some are even beneficial. Only a few species are known to be disease-causing.

Microorganisms called bacteria to occur in a variety of types. They may take the shape type of spheres, rods, or spirals. There are pathogenic, or harmful, microbes that cause disease, but there are also beneficial for human life.

As an example, our digestive tract and gut contain bacteria that are essential to our bodies ability to operate normally. The intriguing thing about microbes is that they make up a whopping 10 times as many cells in our body as human cells do. Additionally, microbes are crucial to biotechnology. They are crucial in that they will once more assist the body in maintaining a healthy condition.

While some bacteria are dangerous, the majority have beneficial functions. They are employed in industrial and medical procedures and maintain a wide variety of living forms, including both plant and animal life.

They typically have a length of a few micrometers and live in millions-strong groups. There are usually 40 million microbes cells per gram of soil. Typically, one million microbes cells can be found in one milliliter of fresh water. At least 5 nonillion microbes are predicted to exist on the planet, and microbes are thought to make up a large portion of the biomass.

2. Different types of Bacteria:

Bacteria come in a wide variety of types. One approach to categorizing them is according to shape. The fundamental shapes are three.

  1. Spherical: The ball-shaped bacteria are called Cocci, and a coccus is a single bacterium. The streptococcus genus, which causes “strep throat,” is one example.
  2. Rod Shaped: They are referred to as bacilli (singular bacillus). Some bacteria with a rod shape are curved. They are called vibrio. Bacillus anthracic (B. anthracic), sometimes known as anthrax, is one example of a rod-shaped bacterium.
  3. Spiral: They are called spirilla (singular spirillus). They are classified as spirochetes if their coil is extremely tight. This type of bacteria can cause syphilis, leptospirosis, and Lyme disease.

Each shape group contains a wide range of different types.

3. Structure of Bacteria:

Animal and plant cells are not the same as bacterial cells. Since bacteria are prokaryotes. They have no nucleus.

The bacteria cell contains:

  • Capsule: A layer that certain bacteria have on the outside of their cell walls.
  • Cell wall: A layer composed of peptidoglycan polymer. The type of bacteria is determined by its cell wall.
  • Bacteria its shape: It is found on the outer side of the plasma membrane. Some bacteria have thicker cell walls, called Gram-positive bacteria.
  • Plasma Membrane: This produces energy and transfers substances inside the cell wall. Since the membrane is transparent, substances can move through it.
  • Cytoplasm:  A gelatinous fluid with ribosomes and genetic material within the plasma membrane.
  • DNA: This has all of the genetic information required for the bacterium’s growth and operation. DNA is present within the cytoplasm.
  • Ribosome: In this process, proteins are synthesized or manufactured. Granules rich in RNA make up the complex structures known as ribosomes.
  • Flagellum: This is how some bacteria are moved and used for locomotion. Some have the capacity to have multiples of it.
  • Pili: The outside of the cell has hair-like structures that help the cell attach to surfaces and spread genetic material to other cells. By doing this, disease in people may spread more quickly.

4. Feed:

Bacteria get their feed in different ways.

The source of energy for heterotrophic is the consumption of organic carbon. The majority take up dead organic matter, like decaying meat. While some of these parasitic microbes harm their host, others aid it.

Simply put, autotrophic bacteria (or just autotrophs) produce their own food by either:

  • Photosynthesis: It uses sunlight, water, and carbon dioxide to produce feed.
  • Chemosynthesis: It uses carbon dioxide, water, and chemical substances such as ammonia, nitrogen, sulfur, and others.

Photoautotroph is bacteria that utilize photosynthesis. Some of them, like cyanobacteria, generate oxygen. These most likely contributed significantly to the production of oxygen in the earth’s atmosphere. Others don’t make oxygen, such as heliobacteria.

Chemoautotroph is those who utilize chemosynthesis. Common locations for these bacteria include ocean vents and the roots of legume plants like alfalfa, clover, peas, beans, lentils, and peanuts.

5. Living Environment of Bacteria:

Bacteria can be found in hot springs, polar ice and glaciers, soil, water, plants, animals, radioactive waste, and deep inside the crust of the earth. Microbes can be found in the stratosphere, between 6 and 30 miles up in the atmosphere, as well as in the deepest parts of the ocean, 10,000 meters or 32,800 feet below the surface.

Bacteria that can only develop in the presence of oxygen are known as aerobes. Some forms, such as corrosion, fouling, issues with water purity, and offensive smells, can negatively impact the environment.

Bacteria known as anaerobes can only flourish in an environment devoid of oxygen. This primarily occurs in the gastrointestinal tract in humans. They are also capable of causing most oral infections, gas, gangrene, tetanus, and botulism.

Although facultative anaerobes can survive in both oxygen-containing and oxygen-free environments, they prefer the latter. They are primarily present in vegetation, soil, water, and some types of normal human and animal flora. Among the examples is Salmonella.

The majority of human infections are caused by mesophiles or mesophilic microbe. They do best in temperatures around 37 °C, which are mild. The body’s temperature is shown here.

Staphylococcus aureus, Pseudomonas maltophilia, Thiobacillus Novellus, Streptococcus pyrogens, Streptococcus pneumonia, Escherichia coli, and Clostridium kluyveri are a few examples of Bacteria.

  • Mesophilic bacteria that are good for you, like dietary Lactobacillus acidophilus, are part of the human intestinal flora or gut microbiome.
  • Extremophiles, also known as extremophilic, can survive conditions that are thought to be too harsh for most living forms.
  • Thermophiles can survive in temperatures as high as 75 to 80°C, and hyperthermophiles can endure temperatures as high as 113°C.

In the depths of the ocean, microorganisms exist around thermal vents where the temperature and pressure are high in complete darkness. By oxidizing sulfur that comes from deep within the soil, they produce their own nourishment.

Some additional extremophiles are:

  • Exclusively occurring in salty environments are halophiles
  • Extremophiles can survive in conditions where no other organism can, including acidophiles, some of which can tolerate pH 0 environments,
  • Alkaliphiles, which can tolerate alkaline environments up to pH 10.5 habitats
  • Psychrophiles, which are found in frigid environments, such as glaciers

6. Reproduction and Transformation of Bacteria:

Bacteria can reproduce and transfer through the following processes:

  • Binary fission: A process of asexual reproduction in which a cell continues to expand until a new cell wall emerges through the center, dividing the original cell into two. The genetic material from these divides into two cells.
  • Transfer of genetic material: Through processes called conjugation, transformation, or transduction, cells receive new genetic material. These mechanisms can strengthen germs and increase their resistance to dangers like antibiotic medicines.
  • Spores: Spores can form when certain bacteria have insufficient nutrients. The organism’s DNA is stored in spores, which also have germination-related enzymes. They can survive a lot of environmental stress. Until the proper conditions are met, the spores can remain dormant for hundreds of years. After that, they might turn back into bacteria.
  • Spores are capable of surviving periods of environmental stress, such as ultraviolet (UV) and gamma radiation, desiccation, hunger, chemical exposure, and high temperatures.

While some microbes create exospores, which are expelled outside, other microbes make end-spores or internal spores. Cysts are what they are.

An example of bacteria that produce endospores is Clostridium. There are around 100 species of Clostridium, including Clostridium botulinum (C. botulinum), often known as botulism, which is the cause of colitis and other intestinal issues, as well as Clostridium difficile (C. Difficile), which is the source of potentially fatal food poisoning.

7. Uses of Bacteria:

While many bacteria are helpful, they are frequently perceived unfavorably. Without them, we wouldn’t be here. It’s likely that microbes’ activity produced the oxygen we breathe.

7.1 Human survival:

Many microbes in the body are crucial to human existence. Digestive system bacteria convert complex carbohydrates and other nutrients into forms the body can utilize.

By taking up spaces that pathogenic, or disease-causing, bacteria wish to adhere to, non-hazardous microorganisms also aid in the prevention of diseases. Some microbes defend us from illness by destroying infections.

7.2.  Nitrogen fixation:

When bacteria die, they absorb nitrogen and release it for use by plants. To survive, plants require nitrogen in the soil, yet they are unable to provide it on their own. Many plant seeds contain a tiny container of bacteria that is used when the plant emerges in order to guarantee this.

7.3.  Food Technology:

Foods like cheese, soy sauce, natto (fermented soybeans), vinegar, yogurt, and pickles are all prepared using lactic acid bacteria, such as Lactobacillus and Lactococcus, together with yeast and molds or fungi.

Foods preserved through fermentation can also potentially be beneficial to your health.

For instance, certain fermented meals include bacteria that are comparable to those associated with digestive health. New chemicals produced by some fermentation processes, such as lactic acid, seem to have anti-inflammatory properties.

The advantages of fermented foods for health still require further study.

7.4.  Bacteria in industry and research

Organic materials can be broken down by bacteria. This is helpful for tasks like trash processing and cleanup of toxic waste and oil spills. In order to produce some chemicals, the pharmaceutical and chemical industries use microbes.

Molecular biology, biochemistry, and genetic studies all use microbes because of their fast growth and simplicity of manipulation. Researchers utilize microbes to examine how genes and enzymes function.

Antibiotics are produced by bacteria.

Bacteria called Bacillus thuringiensis (BT) can be used in place of pesticides in agriculture. It doesn’t have the negative environmental effects that come with using pesticides.

8. Risks of Bacteria:

Human diseases like cholera, diphtheria, dysentery, bubonic plague, pneumonia, tuberculosis (TB), typhoid, and many more can be caused by specific types of bacteria.

The immune system will kill germs that the human body does not perceive as beneficial if it is exposed to them. This response may result in the swelling and inflammation we observe, for instance, in an infected wound.