Sheet1Chapter #1 Discovery of MicroorganismsYearScientist nameWorkingAround 1658Athanasius KircherHe had seen minute living worms in putrid meat and milk by using the microscope. Magnification power of this microscope was so low that he could not have seen bacteria.1664Robert HookeDescribe the Structer of molds. 1676-1683LeeuwenhoekHowever, probably the first person to see different types of microorganisms. Especially bacteria, under a microscope that probably did not have a magnification power above 300x. He observed bacteria in saliva, rainwater, vinegar, and other materials; sketched the three morphological groups (spheroids or cocci, cylindrical rods or bacilli, and spiral or spirilla); and also described some to be motile. He called them animalcules.He reported his observations to the newly formed scientific organization, The Royal Society of London, where his observations were read with fascination. As reasonably good microscopes were not easily available at the time, other interested individuals and scientists during the next 100 year only conformed his observations.1838Ehrenberg Introduced the term bacteria and had proposed at least 16 species in four genera.1875Ferdinand CohnHe had developed the preliminary classification system of bacteria. Coln also was the first to discover that some bacteria produced spores.1940Although, like bacteria the existence of submicroscopic viruses was recognized in the mid 19th century, they were observed only after the invention of the electron microscope.Where are they from?LeeuwenhoekThere were no bursts of activity, some scientific minds were curious to determine from where the animalcules, observed to be present in many different objects, were emanating. Society had just emerged from Renaissance period, and science, known as experimental philosophy, was in its infancy.The theory of spontaneous generation, i.e., the generation of some from of life from nonliving objects, had may powerful followers among the educated and elite classes. Since the time of the Greeks, the emergence of maggots from dead bodies and spoiled flesh was thought to be due to spontaneous generation.1665RediHe disproved that theory by showing that the maggots in spoiled meat and fish could only appear if flies were allowed to contaminate them. The advocates of the spontaneous generation theory argued that the animalcules could not regenerate by themselves (biogenesis), but they were present in different things only through abiogenesis (Spontaneous generation). 1749Turbevill Needham He showed that boiled meat and meat broth, following storage in covered flasks, could have the presence of these animalcules by spontaneous generation.1765Lazzaro Spallanzani Showed that boiling the meat infusion in broth in a flask and sealing the flask immediately prevented the appearance of these microscopic organisms, thereby disproving Needham's theory.Antoine Laurent LavoisierThis was the first time when Antoine and his coworkers showed the need of oxygen for life. The believers of abiogenesis rejected Spallanzani's observation, suggesting that was not enough vital force (oxygen) present in the sealed flask for animalcules to appear through spontaneous generation1830SchulzeBy passing air through acid, showed that bacteria failed to appear in boiled meat infusion even in the presence of air.1838Theodore SchwannBy passing air through red hot tubes, showed that bacteria failed to appear in boiled meat infusion even in the presence of air.1854SchroederBy passing air through cotton, showed that bacteria failed to appear in boiled meat infusion even in the presence of air.1895Harry RussellShowed that gaseous swelling with bad odors in canned peas was due to growth of heat resistant bacteria (Spores)Food borne Diseases1820Justin Kerner He described food poisoning from eating blood sausage (due to botulism). Fatal disease form eating blood sausage was recognized as early as A.D 900.1849John SnowHe suggesed the spread of cholera through drining water contaminated with sewage. 1854Filoppo FaciniHe named the cholera bacilli as Vibrio cholera, which was isolated in pure from Robert Koch in 1884.1856William BuddHe suggested that water contamination with feces from infected person spread typhoid fever and advocated the use of chlorine in water supply to overcome the problem.1800G.de Morveau & W.CruikshankThey advocated the use of chlorine to sanitize potable water.1885Theodor EscherichHe isolated Baacterium coli (later named Escherichia Coli) from the feces and suggested that some strains were associated with infant diarrhea.1888A.A. Gartner He isolated Bacterium enteritidis (later Salmonella)from the organs of a diseased man as well as from the meat the man ate.1896Marie von ErmengemHe proved that Salmonella caused a fatal disease in humans who consumed contaminated sausage.1894J. DenysHe associated pathogenic Staphylococcus with death of a person who ate meat prepared from a diseased cow.1895Marie von ErmengemHe isolated Bacillus botulinus (Clostridium botulinum) from contaminated meat and proved that it caused botulism.Microbiology Techniques1854Heinrich Schroder & theodore con duschThey used cotton to close tubes and flasks to prevent microbial contamination in heated culture broths.1876Car WeigertHe used methylene blue (A synthetic dye) to stain bacteria in aqueous suspensions. 1877Fredinand CohnHe showed heat resistance of bacillus subtilis endospores.1878Joseph ListerHe Isolate Streptococcus lactis (Now Lactococcus) in pure culture by serial dilution from sour milk.1880Robert KochHe & his associates introduced many important methods that are used in all branches of microbiology, such as solid media (First Gelatin then agar) to purify and enumerate bacteria, petri dish, flagellar staining,steam sterilization of media above 100 and photography of cells and spores.1884Hans Christian GramHe developed gram staining of bacteria cells.

Sheet3Louis PasteurFinally, demonstrated that, in boiled infusion, bacteria could grow only if the infusions were contaminated with bacteria carried by dust particles in air. His careful and controlled studies proved that bacteria were able to reproduce (biogenesis) and life could not originate by spontaneous generation. Louis PasteurShowed that wine fermentation from grapes and souring of wine caused by microorganisms. He also proved that spoilage of meat and milk was associated with the growth of microorganisms . Later, he showed the association of microorganisms with several diseases in humans, cattle and sheep, and he also developed vaccines against a few diseases and animal diseases caused by microorganisms, including rabies.Louis PasteurThe major developments of ideas on the possible roles of microorganisms in foods and their scientific proof were initiated Louis PasteurHe proved that the organism which was present on surface of wine, during vinegar production that was associated with the alcohol to acetic acid and named it Mycoderma aceti.Louis PasteurHe showed that fermentation of lactic acid and alochol from sugar was the result of growth of specific bacteria and yeasts, respectively.Louis PasteurHe recommended heating of wine at 62.7 OC for 30 min to destroy souring bacteria. F.Soxhlet advanced boiling of milk for 35 min to kill contaminated bacteria. Later, this method was modified and named pasteuization and used to kill mainly vegetative pathogens and many spoilage bacteria.

Sheet2Ehrenberg Introduced the term bacteria and had proposed at least 16 species in four genera.Charles He suggested that growth of yeasts was associated with alcohol fermentation C.J. Named the microscopic organisms found on the surface of wine during vinegar production as Mycoderma mesentericum.Emil Christian He used pure cultures of yeasts of ferment beer.Ferdinand CohnHe had developed the preliminary classification system of bacteria. Coln also was the first to discover that some bacteria produced spores.Filoppo FaciniHe named the cholera bacilli as Vibrio cholera, which was isolated in pure from Robert Koch in 1884.Fredinand CohnHe showed heat resistance of bacillus subtilis endospores.G.de Morveau & W.CruikshankThey advocated the use of chlorine to sanitize potable water.Hans Christian GramHe developed gram staining of bacteria cells.Harry RussellShowed that gaseous swelling with bad odors in canned peas was due to growth of heat resistant bacteria (Spores)Heinrich Schroder & theodore con duschThey used cotton to close tubes and flasks to prevent microbial contamination in heated culture broths.Hermann HelmholtzThey proposed that putrefaction and fermentation were connected with the presence of the organisms derived from air.J. DenysHe associated pathogenic Staphylococcus with death of a person who ate meat prepared from a diseased cow.Joh TyndallShowed that boiled infusion could be stored in dust free air in a box without microbial growth.John SnowHe suggesed the spread of cholera through drining water contaminated with sewage. Joseph ListerHe Isolate Streptococcus lactis (Now Lactococcus) in pure culture by serial dilution from sour milk.Lazzaro Spallanzani Showed that boiling the meat infusion in broth in a flask and sealing the flask immediately prevented the appearance of these microscopic organisms, thereby disproving Needham's theory.