Hello everyone. Welcome to the channel The Pharmacy Talks. Today in this lecture we are going to discuss about the history of microbiology. So before starting today's discussion, please subscribe to our channel if you're new here and press the bell icon. So let's begin. Microbiology is the study of living organisms of microscopic size. The term microbiology was given by French chemist Louis Pasteur. Microbiology is said to have its roots in the great expansion and development of the biological sciences that took place after 1850. The term microbe was first used by Sedolet in 1878. The history of microbiology can be classified into four different eras. They are Discovery Era, Transition Era, Golden Era, and the Modern Era. Now we'll discuss about them one by one. First is the discovery era. Aristotle proposed the spontaneous generation theory. He stated that living organisms could develop from non-living materials. In the 13th century, Robert Bacon described that the disease is caused by a minute seed or germ. Robert Hooke, a 17th century English scientist, was the first to use a lens to observe the smallest unit of tissues he called cells. Soon after, The Dutch amateur biologist Antonie van Leeuwenhoek observed what he called animalcules with the use of his home-made microscopes. Leeuwenhoek was the first person to produce precise and correct descriptions of bacteria and protozoa using a microscope he made himself. Because of this extraordinary contribution to microbiology, he is considered as the father of microbiology. Leeuwenhoek is also considered to be the father of bacteriology and protozoology. He wrote over 200 letters which were transmitted as a series of letters from 1674 to 1723 to Royal Society in London during a 50 years period. Next is transition era. When microorganisms were known to exist, most scientists believed that such simple life forms could surely arise through spontaneous generation. That is to say life was thought to spring spontaneously from mud and lakes or anywhere with sufficient nutrients. This concept was so compelling that it persisted until late into the 19th century. The main aspects were to solve the controversy over spontaneous generation which includes experimentations mainly of Francesco Redi, John Needham, and Lazaros Polanzani. Francesco Redi contributed a lot in the field of microbiology. The ancient belief in spontaneous generation was first of all challenged by Reedy, an Italian physician, who carried out a series of experiments on decaying meat and its ability to produce maggots spontaneously. He proved that microorganisms are present in atmosphere. John Needham was probably the greatest supporter of the theory of spontaneous generation which was proposed by Aristotle. He proposed that tiny organisms or the animalcules. arose spontaneously on his mutton gravy. He covered the flasks with cork as done by Reedy and even heated some flasks. Still the microbes appeared on mutton broth. Lazaros Polanzani was the other scientist who by doing his experiments proved that air carries germ. He was an Italian naturalist who attempted to refute Needham's experiment. He boiled beef broth for longer period, removed the air from the flask and then sealed the container. Followed incubation no growth was observed by him in these flasks. He showed that the heated nutrients could still grow animalcules when exposed to air by simply making a small crack in the neck. Thus Palanzani disproved the doctrine of spontaneous generation. Next is Golden Era. The golden age of microbiology began with the work of Louis Pasteur and Robert Koch who had their own research institute. During this period, we see the real beginning of microbiology as a discipline of biology. Louis Pasteur is considered as the father of medical microbiology. The concept of spontaneous generation was finally put to rest by the French chemist Louis Pasteur in an inspired set of experiments involving a goosenecked flask. The discoveries of the principles of vaccination, microbial fermentation and pasteurization were given by him. He was the first to discover vaccines for rabies and anthrax. He was the first to propose germ theory. The discovery of chicken cholera vaccine by Louis Pasteur revolutionized the work in infectious diseases and can be considered as the birth of immunology. He gave the notion of using a weakened form of the disease to provide immunity. He gave the vaccination concept by live attenuated vaccine against rabies. John Tyndall who was an English physicist, deal a final blow to spontaneous generation in 1877. He conducted experiments in an aseptically designed box to prove that dust indeed carried the germs. He demonstrated that if no dust was present, Sterile broth remained free of microbial growth for indefinite period even if it was directly exposed to air. He discovered highly resistant bacterial structure, late known as indospore, in the infusion of hay. Prolonged boiling or intermittent heating was necessary to kill these spores, to make the infusion completely sterilized, a process known as tindalization. Lord Joseph Lister was a famous English surgeon is known for his notable contribution to the antiseptic treatment for the prevention and cure of wound infections. He is known as the father of antiseptic surgery. Edward Jenner was an English physician was the first to prevent smallpox. He contributed a lot in vaccination. The credit for the discovery of this first wonder drug penicillin in 1929 goes to Sir Alexander Fleming of England. He discovered penicillin from Penicillin notatum. Paul Ehrlich gave his contribution in the treatment of syphilis by arsenic. Ehrlich's work had laid important foundations for many of the developments to come and the use of salvasin marked the beginning of the idea of chemotherapy and the use of chemicals that selectively inhibit or kill pathogens without causing damage to the patient. Next is modern era. By the end of 1900, science of microbiology grew up to the adolescence stage and had come to its own as a branch of the more inclusive field of biology. In the later years the microorganism were picked up as ideal tools to study various life processes and thus an independent discipline of microbiology, molecular biology was born. Many Nobel laureates have their huge contribution in the field of microbiology. Von Buring contributed in depth antitox. Ronald Ross in malaria. Robert Koch in tuberculosis. Metinkoff in phagocytosis. Fleming in penicillin. Watson and Crick in the structure of DNA. Holley, Coroner in genetic code. Prisoner in prions. And Brenner.