Microorganisms Essential to Human Existence on The Planet

Microorganisms play an important part in decay and the release of nutrients from dead organisms and their waste products (Clegg and Mackean, 2000). Although some cause disease, humans would not exist if there were no input on the ecosystem.

Bacteria play an important role in the global ecosystem, however, decomposition is one of the most important roles of bacteria. It is described as the breakdown of organisms and the release of nutrients back into the environment (Ucmp.berkeley.edu, 2018). Another important role of bacteria is cycling of nitrogen. Plants rely on nitrogen with the use of soil to help them with their health and growth, and it cannot be obtained from the gaseous nitrogen in the atmosphere. These two roles are vital component for maintaining human life. The earth’s atmosphere is made up of 78% nitrogen, 22% of oxygen, carbon dioxide and other greenhouse gases (Fullick, 1994). Nitrogen is a naturally occurring element that is essential for growth and reproduction in both plants and animals (Science and Earth, 2018). For plants and animals to obtain nitrogen, it needs converting into nitrates, nitrogen compounds mixed with hydrogen.

Although nitrogen gas makes up 78% of the Earth’s atmosphere, it is very unreactive, meaning that it is impossible for plants to use it directly. Instead, they need a supply of fixed nitrogen such as ammonium ions (NH4+) or nitrate ions (NO3-). All nitrogen-fixing organisms are free-living in the soil, whereas others are endophytic (Campbell et al, 2014). The bacteria involved include Cyanobacteria and organisms such as the rhizobium bacteria form efficient and intimate associations with the roots of legumes. The product of the initial stages of nitrogen fixation is ammonia. In the soil, ammonia is then rapidly converted to nitrates by bacteria such as Nitrosomas and then nitrates by other bacteria such as Nitrobacter. In leguminous plants, amino acids are synthesized directly using ammonia resulting from the initial nitrogen fixation. The nitrates produced by nitrogen fixation are used to form protein of plant and subsequently animal tissue. The nitrogen is eventually released from the dead decaying tissues of both plants and animals by the action of yet more bacteria such as thiobacilus deitficans (Fullick, 1999).

Lightening is another way that nitrogen can be converted into nitrogenous compounds that can be used by plants and animals. Lighting strikes when nitrogen fixation occurs, and only accounts 10% of nitrogen fixation around the world (OCR A2 Biology Student Book, 2008).

There are different types of foods and drinks that are produced with the help of microorganisms, however, yeast is a type of fungus that is used in different ways in the production of breads, beer and wines. The most common form of yeast used in breads is saccharomyces cerevisiae (Hocking et al, 2008). It can use aerobic respiration, respiration with the presence of oxygen. During this process, the yeast is used as sugar and the sugars present in the flour as it’s food. It is broken down to provide the yeast with the energy to rise. The yeast rises by budding and as it happens, the bubbles of the gas carbon dioxide are produced in the dough. The bubble makes the dough expand because the dough becomes sticky and it stops the bubbles and preventing them from escaping. Once the dough is baked, the heat kills the yeast and the dough stops expanding (Microbiologyonline.org, 2018).

Production of food is another role of bacteria. Lactobacillus bulgaricus is a common form of bacteria found in yogurts. It converts lactose and the sugar present in milk into lactic acid. This form of bacteria is very beneficial to the body and it prevents the growth of harmful bacteria in the small intestine by keeping the pH low (Jones and Jones, 2002). Food consumption leads to a lot of waste products being produced. Therefore, sewage can be very harmful because it contains different microorganisms that can be very pathogenic and can cause health problems. However, there are certain types of microorganisms that helps in producing clean safe water. These include the three stages of sewage treatment and disposal. The first stage is the primary treatment the involves the removal of large objects e.g. rags and woods (Jones and Jones, 2002). The screen traps the debris allowing water to flow. During primary treatment, the waste water flows into a tank and the solid within the solution sinks to the bottom enabling the water to flow into the third stage. During the secondary stage treatment, the settled sewage is sprinkled into a filter bed which houses various forms of microorganisms that fed on the sewage.

Fungi and saprotrophic bacteria feed saprotrophically. Therefore, they secrete their enzymes onto dead matter and are responsible for digesting waste into small molecules. These molecules are absorbed by the microorganisms and are stored to release energy. Their input in decomposing waste enables clean water to be produced (Hocking et al, 2002).
Biotechnology is another use of microorganisms in maintaining human life on planet. It uses genetic engineering to overcome problems which allows certain organisms to use a gene from another organism for example, people suffering from diabetes do not produce insulin or hormone that regulates concentration of glucose in the blood (Campbell et al, 2014).
In conclusion, microorganism is vital for maintaining human life on planet, however, they are more than a disease-causing agent. Few are known to be pathogenic, but more has an important role in maintaining human health. Microorganisms are crucial, and they have proven to have a role in ensuring the existence of human’s planet.