Microorganisms are a type of organism which is not visible to human eyes and hence called microscopic. There are various types of microorganisms, such as fungi, bacteria, protists, viruses, and archaea. Most of the microorganisms belong to the earliest life forms. Microbes can be parasitic or free-living. Many microorganisms are single-celled in other words, unicellular organisms. Microbes live everywhere on land, water, etc. Some of the microorganisms exist in the most extreme conditions and are called extremophiles. Microorganisms operate decomposition and hence are very vital in nutrient recycling. Even in the nitrogen cycle, microorganisms play a significant role. Not all microbes or microorganisms spread diseases. There are many which help in various natural processes and keep up the wellness of the ecosystem.
Though the existence of microorganisms seems to be from many centuries, they came to light in the 17th century.
Some tiny organisms claimed to exist and were called nigodas by the present-day Jains. Nigodas are born in clusters; live in every place, including bodies of people, plants, and animals.
The first idea that microbes spread diseases was indicated by roman scholar Marcus Terentius Varro in his book.
About two centuries before Antonie Van Leeuwenhoek's discovery by experimentation, Akshamsaddin wrote in his book Maddat ul-Hayat referring to microbes as a material of life.
Antonie Van Leeuwenhoek did various experiments on microbes and observed them. He is referred to as the father of microbiology.
Louis Pasteur also made different observations and contributed to the statement that microbes spread diseases.
Robert Koch certified that microbes could be the reason for causing diseases.
The three main categories of microbes from which all others appeared are bacteria, Archaea, and eukaryote.
Microbes have evolved faster as compared to other organisms. The main reason behind it is the rate of reproduction. Microbes can reproduce at a very high rate.
Archaea comes under prokaryotes and are unicellular. The characteristic of a prokaryote is not having a nucleus in the cell or other organelles. Archaea differ from the bacteria biologically as well as in genetics.
The combination of Archaea and bacteria form the highest diverse set of organisms on earth and they live in all habitats.
Bacteria also belong to prokaryotic organisms. Bacteria can grow very rapidly if the conditions are optimum. They reproduce by processes such as budding and binary fission. They do not go through sexual reproduction including meiosis.
Eukaryotes form all the living things that are visible to the naked eye, inclusive of humans. But many eukaryotes are also microbes.
The microbes that live free obtain energy in various ways. Some adapt to photosynthesis, just like plants — some help in breaking down natural chemicals and produce energy. Most of them feed on dead things due to which the decaying happens.
We call certain microbes as germs because they cause diseases. Such microbes are called parasites that survive by taking upon other living things. Parasites cause mumps, measles, and chickenpox. Such parasites are known as viruses. Storing and properly preparing food can avoid microorganisms from manifesting and spreading diseases.
Microorganisms are omnipresent, and they are present in the food we eat, the air we breathe, the water we drink, the place we sit, stand, etc. They are cosmopolitan. They can even be present in the thermal geysers, vents, etc. (extremophiles).
Now, let us see various fields where microbes can help.
Microbes in household products:
The conversion of milk into curd occurs due to the presence of lactobacillus bacteria.
This lactic acid bacteria improves nutritional quality by enhancing vitamin B12.
The dough we prepare for idli, dosa, is fermented using fungi and bacteria.
Baker’s yeast (Saccharomyces cerevisiae) helps in the fermentation of bread.
In many traditional drinks and foods, fermentation happens using bacteria. (Eg: Toddy).
Microbes can help fish, soybean, and bamboo shoots in fermentation.
Propionibacterium shermanii helps in the making of swiss cheese.
Ripening of Roquefort cheese is done by growing fungi on them to produce distinct flavor.
Microbes in industrial products:
Many antibodies and beverages can be manufactured using microorganisms.
Yeast assists the fermentation process in the manufacturing of wine, Whisky, Rum.
Saccharomyces cerevisiae or brewer's yeast aids the fermentation of malted cereals, fruit juices to produce ethanol.
Microbes in Antibiotics:
Penicillin, the first antibiotic discovered, is also developed using a microorganism known as Penicillium notatum.
This penicillin helped in healing for wounded soldiers during world war II.
Some other fatal diseases like Plague, whooping cough, Diphtheria, and leprosy can be treated using these antibiotics produced from microorganisms.
Microbes in sewage treatment:
Bacteria help to treat sewage water from municipal waste. It uses anaerobic respiration, BOD, etc. to treat the water.
Microbes in production of biogas:
Methanogen bacteria help in the production of biogas.
Microbes in chemicals, enzymes, and other bioactive molecules:
Aspergillus niger is present in citric acid. It is a fungus.
Acetobacter acetic is available in acetic acid.
Clostridium butylicum bacteria in butyric acid.
Lactobacillus is present in lactic acid.
Lipases are an essential part of detergents.
Pectinases help in storing the bottled juices.
Streptokinase enzyme used to remove blood clots from the blood vessels of myocardial infarction patients.
Cyclosporin A acts as an immunosuppressive agent, and Cyclosporin A enzyme is produced by the eubacterium Trichoderma polysporum.
Monascus purpureus yeast produces statins which are used as blood cholesterol-lowering agents.
Microbes are used in various parts of our day to day life, including some industries, and they are equally useful for nature.
Some fungi and bacteria species help in the creation of steroids, which are used to inject to humans for various purposes.
Specific bacteria and fungi are also used to create protection from some insects and pests in agriculture.
Microbes play a vital role in keeping up the soil fertility. They do the process of composting and help in the formation of manure. This manure improves the fertility of the soil by enhancing nutrients such as nitrates.
Microbes are vastly used in the research field. The creation of various vaccines is also aided by microbes and research using them.
Microbes assists in the analysis and research done on DNA and RNA.
Microbes can take or consume nitrate from the air, and hence they are essential in the nitrogen cycle.
Microorganisms or microbes have existed in nature for a very long time. Microbes have evolved quickly and have become useful for the environment as well as for living beings.The existence of both harmful and good bacteria provides a proper balance in the ecosystem. Microbes come under the bad category if they aid in spreading diseases and harming other living beings. Microbes come under good category if they help in various productions such as yeast, curd, and steroids so on. A lot of research work is done on the microbes, and various vaccines use microbes. There are innumerable uses of bacteria in the ecosystem, some of which may have not been found yet. Microbes are the backbone for production industries, especially food-related. Without microbes, the production of curd will cease to exist, and also bread will no longer be part of the food for living beings like humans. Hence bacteria have a bad side and a good side as well. The bad side has to stay under control, and the good side must not get exploited, which will keep a balance in the ecosystem.