As per Big Bang theory, the universe originated with a big explosion, followed by emergence of star, solar system and finally the Earth. At the early times the Earth was very hot and contained mainly volcanoes, which during the period of time cooled down and water came into existence due to condensation of gases and rain. The first form of life came into existence about 3.5 billion years ago in the form of microbes and they made the Earth livable. Later, all the forms of life like plants and animals originated during the process of evolution in due course of time.
Generally microbes included the entire living organism too small to be seen by naked eyes like virus, bacteria, fungi, algae, protozoa, nematodes and many more but there are some microbes which are exception to it and are even bigger than trees like sea weeds. According to one estimate 1 g of soil contains more than 109 microbes. One interesting fact about the microbes is that the microbes are highly adoptive in their nature and can grow at a lower temperature even < 5°C to a higher temperature even 110°C. Further some microbes can tolerate almost 3000 times more radiation than human beings. Due to the highly adoptive nature and tolerance they can grow in all the types of habitats ranging from snow, normal soil/water to highly saline soil/water, boiling sulfur springs, rocks and even in deserts. In an experiment by USA, bacteria were sent to moon in 1967 with Surveyor 3 and were found to survive for the period of 2.5 years on moon without any water or atmosphere.
Microbes are such smaller organisms that a small tip of a pin can hold thousands of bacteria. The forms can vary from most simple viruses having only protein and nucleic acid to prokaryotic bacteria, eukaryotic fungi, algae, protozoa and nematodes. The forms also show the variety like edible and non edible algae, sea weeds, mushrooms etc. However, only 10% microbes have been characterized and a huge hidden wealth is unknown to science which they may be exploited for various biotechnological and pharmaceutical applications.
It’s a myth since long that microbe causes diseases and miseries in human society but the fact is that most of the micro-organisms are not only harmless but they are helpful to mankind in day to day life. The microbes are present in the elementary canal of the animals and human beings helping in digestion of the food. They also produce essential vitamin B complex in the body, which are otherwise not produced by the human body. No doubt some microbes are involved in the human as well as plant pathogenesis but majority of them are useful for mankind. Their application in the fields of agricultural, environmental and medical biotechnology, food and beverage production, as alternate source of energy etc is well known and documented. In short, it can be concluded that without microbial intervention, the life will come to stand still.
Out of numerous uses, microbes being food is the most sought off property. Algae and mushrooms are the typical example of the microbial food. Being rich in protein, vitamins, minerals and deficient in sugars, the microbial food has got a position of delicacy in the human society. The marine algae also form the part of designer food. Further, all the fermented delicacies of north and south Indian foods are mediated by the microbes. On the other hand, the various alcoholic beverages are also produced by the microbial intervention.
Not only the food of human being but also the microbes are useful for the production of the medicine like penicillin, streptomycin and other antibiotics. Recently, it has been discovered that some of the mushrooms possess high gastronomical as well as medicinal properties like anticancer, anti-HIV, anti-angiogenic, hypocholesterolemic, anti-histamine release, anti-platelet aggregation and many more. It has also been observed that mushroom normalizes the homeostasis in human body by lowering blood pres