How Microorganisms Live in Our Body

Microorganisms make up a large part of the planet’s living material and play a major role in maintaining the Earth’s ecosystem. Microorganisms are the tiny organisms that cannot be seen by the naked eyes. They are microscopic and are usually known for producing diseases to animals and human being. A microorganism is a microscopic living organism, which may be single celled or multicellular and the study of microorganism is known as microbiology. (Campbell et al., n.d.)

Microorganisms have great impact on human lives and are used for various purposes and participate in various cycles. Bacteria are key to nitrogen cycle. There are four main parts of the nitrogen cycle and bacteria play a role in all of them. Nitrogen gas is converted to nitrate compounds by nitrogen-fixing bacteria in soil or root nodules. Lightning also converts nitrogen gas to nitrate compounds. The Haber process converts nitrogen gas into ammonia used in fertilizers. Ammonia is converted to nitrates by nitrifying bacteria in the soil.

Plants absorb nitrates from the soil and use these to build up proteins. The plant may be eaten by an animal, and its biomass used to produce animal protein. Urea and egested material is broken down by decomposers. This results in nitrogen being returned to the soil as ammonia. Decomposers also break down the bodies of dead organisms resulting in nitrogen being returned to the soil as ammonia.

In some conditions denitrifying bacteria in the soil break down nitrates and return nitrogen to the air. This is usually in waterlogged soil. Improving drainage reduces this effect, making the soil more fertile. (Mary Jones, 2008) Production of many foods is possible with the help of microorganism. E.g. foods like bread, beer and cheese are produced with the help of yeast. Similarly, bacteria are involved in the production of butter, yoghurt, many kinds of chocolates, coffee and other foods of daily life.

It is very difficult to decode the human genome if any disorders occur in it as humans are eukaryotic organisms. It means their body consists of various types of cell and they are all differentiated into different tissues and organs. Microorganisms have made it possible to make such medicines which when enter the body, target the defected genes and make healthy changes in them and they become functional again. There is a common example of human insulin. Insulin is an antibiotic which is prescribed for the diabetic patients. Now it is possible to synthesize the insulin in microorganisms like bacteria and yeast. These microorganisms are inserted in the body in the form of vectors and cure the defected genes. (Campbell et al., n.d.)

Our body contains ten times more microorganisms than the body cells. These microorganisms are useful for the body and perform various useful function, for example E. coli (specie of bacteria) resides in the intestine and releases such components which help in the digestion of the food. One purpose of bacteria in the body is to fight against those harmful bacteria which can cause diseases. For example, there is also a bacterium in the gut which helps in synthesizing the vitamins like biotin, vitamin K and folic acid. Biotechnology is one field which has made use of microorganisms most. By using the techniques of biotechnology, scientist have succeeded in developing human growth, growth hormones and other useful components of the body. Biotechnological processes use microorganisms for the drug delivery in the form of vectors and plasmids. Microorganism have provided many beneficial things to agriculture as they are responsible for increasing the fertility of the soil. Due to this, the production of the plants increases, and economy becomes strong. (Pete Kennedy, 2009).

Bacteria present in the environment are responsible for recycling wastes and for producing energy sources like carbon and nitrogen. Plants use carbon dioxide during the process of photosynthesis. More the consumption of carbon dioxide will lead to more production of food. Some bacteria also help in cleaning the environment by digesting the pollutants and as a result they release nutrients which are environment friendly. (Mary Jones, 2008) Microorganism are widespread in nature and are beneficial to life, but some can cause serious harm. They can be divided six major types: bacteria, archaea, fungi, protozoa, algae and viruses.

Bacteria are unicellular organisms. The cells are described as prokaryotes because they lack a nucleus. They exist in four major shapes: bacillus (rod shape), coccus (spherical shape), spirillum (spiral shape) and vibrio (curved shape). Most bacteria have a peptidoglycan cell wall; they divide by binary fission; and they may possess flagella for motility. The difference in their cell wall structure is a major feature used in classifying these organisms. According to the way their cell wall structure strains, bacteria can be classified as either Gram-positive or Gram-negative when using the Gram staining. Bacteria can be further divided based on their response to gaseous oxygen into the following groups: aerobic (living in the presence of oxygen), anaerobic (living without oxygen), and facultative anaerobes (can live in both environments). (Campbell et al., n.d.)

Archaea or archaebacteria differ from true bacteria in their cell wall structure and lack peptidoglycans. They are prokaryotic cells with avidity to extreme environmental conditions. Based on their habitat, all Archaean can be divided into the following groups: methanogens (methane-producing organisms), halophiles (archaeans that live in salty environments), thermophiles (archaeans that live at extremely hot temperature, and phychrophiles (cold-temperature Archaeans. Archaeans use different energy sources like hydrogen gas, carbon dioxide, and sulphur. Some of them use sunlight to make energy, but not the same way plants do. They absorb sunlight using their membrane pigment, bacteriorhodopsin. This reacts with light, leading to formation of the energy molecule adenosine triphosphate (ATP). (Pete Kennedy, 2009).

Some examples of fungi are molds which display thread-like (filamentous) growth and multicellular structures, yeasts which are typically non-filamentous and can be single celled and mushrooms which possess a fruiting body for production of spores. Molds have been used to make pharmaceuticals, including penicillin, which is one of the most commonly prescribed antibiotics, and cyclosporine, used to prevent organ rejection following a transplant. Fungi are eukaryotes cells (with a true nucleus). Most fungi are multicellular, and their cell wall is composed of chitin. They obtain nutrients by absorbing organic material from their environment (decomposers), through symbiotic relationships with plants (symbionts), or harmful relationship with a host (parasites). They form characteristic filamentous tubes called hyphae that help absorb material. The collection of hyphae is called mycelium. Fungi reproduce by releasing spores. (Mary Jones, 2008)

Protozoa are unicellular aerobic eukaryotes. They have a nucleus, complex organelles, and obtain nourishment by absorption or ingestion through specialized structures. They make up the largest group of organisms in the world in terms of numbers, biomass, and diversity. Their cell walls are made up of cellulose. Protozoa have been traditionally divided based on their mode of locomotion: flagellates produce their own food and use their whip-like structure to propel forward, ciliates have tiny hair that beat to produce movement, amoeboid have false feet or pseudopodia used for feeding and locomotion, and protozoans are non-motile. They also have different means of nutrition, which groups them as autotrophs or heterotrophs. (Campbell et al., n.d.)

Algae, also called cyanobacteria or blue-green algae, are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis. They live in water, damp soil, and rocks and produce oxygen and carbohydrates used by other organisms. It is believed that cyanobacteria are the origins of green land plants. (Mary Jones, 2008)

In humans, viruses are responsible for numerous diseases, from the common cold to deadly Ebola. Viruses are noncellular entities that consist of a nucleic acid core (DNA or RNA) surrounded by a protein coat. Although viruses are classified as microorganisms, they are not considered living organisms. Viruses cannot reproduce outside a host cell and cannot metabolize on their own. Viruses often infest prokaryotic and eukaryotic cells causing diseases. (Campbell et al., n.d.)