L1.pdf

L1 YEAR FINDINGS 8000 BC Agriculture & animal husbandry 8000-1000 BC Many foods preservation method like smoking, fermentation … to prevent spoilage 7000 BC Bab...

L1 YEAR FINDINGS 8000 BC Agriculture & animal husbandry 8000-1000 BC Many foods preservation method like smoking, fermentation … to prevent spoilage 7000 BC Babylonians found beer 6000 BC 1st study on food spoilage 3500 BC Wine 3000 BC Egyptian manufactured cheese & butter 1000 BC Roman used snow to preserve shrimp, smoked and fermented meat YEAR SCIENTIST FINDINGS 1658 Athanasius Kircher Using microscope observed minute living worms in putrid milk & meat 1664 Robert Hooke Described structure of molds 1676 Antony Van Leuwenhoek Observed bacteria in saliva, rain water, vinegar Sketched 3 morphological structure --- Spherical—cocci Cylindrical rod--- bacilli Spiral—spirilla Called them Animalcules 1875 Ferdinand Cohn Preliminary classification system of bacteria 1st to discover some bacteria produce spores 1940 Electron microscope SPONTANEOS THEORY About the possibility of life forms being able to emerge from non-living things By Aristotle ---on the generation of animals(book) Vital heat – pneuma YEAR SCIENTIST EXPERIMENT 1626-1697 Francesco Redi Fresh meat in 3 jars Open (presence of maggots), closed, covered with muslin cloth >maggots in spoiled meat and fish could only appear if flies were allowed to contaminate them 1731-1781 John Needham Boiled broth and placed in flask Broth heated--leaved open—then closed (To prove spontaneous gen) 1765 Lazzaro Spallanzani Boiled the broth and sealing the flask immediately after boiling prevented Mold growth an disapproved Needham’s theory Antoine Laurent Lavoisier Found the need of oxygen for life 1830 Schulze By passing air through Acid 1838 Theodore Schwann Passing air through red hot tube 1854 Schroeder Passing air through cotton YEAR NAME FINDINGS 1861 Louis Pasteur boiled infusion, bacteria could grow only if the infusions were (SWANNECK contaminated with bacteria carried by dust particles in air. EXPERIMENT) and life could not originate by spontaneous generation. Father of food microbiology – Louis Pasteur all fermentative processes were caused by microorganisms he published several papers on fermentation between 1857 and 1860. In 1857 he showed that souring milk was caused by microbes and in 1860 he demonstrated that heat destroyed undesirable microbes in wine and beer. he invented a process in which liquids such as milk were heated to a temperature between 60 and 100 °C This killed most bacteria and moulds already present within them. Pasteur patented the process, to fight the "diseases" of wine, in 1865. 1820–1893 JOHN TYNDALL In 1877 Tyndall demonstrated that dust did indeed carry germs and that if dust was absent, broth remained sterile even if directly exposed to air evidence for the existence of exceptionally heatresistant forms of bacteria Tyndallization can be used to destroy the spores It consists of heating the substance to boiling point (or just a little below boiling point) and holding it there for 15 minutes, three days in succession 1752–1841 Francois Nicolas He developed methods to preserve foods in sealed glass bottles Appert by heat in boiling water Nicholas Appert a Paris confectioner who invented the process of canning he opened the first vacuum-bottling factory in 1804 1822 C.J. Person named the microscopic organism found on the surface of wine during vinegar production as Mycoderma mesentericum 1868 PASTEUR proved that this organism was associated with the conversion of alcohol to acetic acid and named it Mycoderma aceti 1898 Martinus Beijerinck renamed it Acetobacter aceti 1837 Theodor Schwann named the organism involved in sugar fermentation as Saccharomyces (sugar fungus) 1838 Charles Cogniard- suggested that growth of yeasts was associated with alcohol Latour fermentation 1860 Louis Pasteur showed that fermentation of lactic acid and alcohol from sugar was the result of growth of specific bacteria and yeasts, respectively 1883 Emil Christian used pure cultures of yeasts to ferment beer Hansen 1804 Francois Nicolas developed methods to preserve foods in sealed glass bottles by heat in Appert boiling water. He credited this process to Lazzaro Spallanzani (1765), who first used the method to disprove the spontaneous generation theory 1819 Peter Durand developed canning preservation of foods in steel cans. 1839 Charles Mitchell introduced tin lining of metal cans. 1870 L. Pasteur recommended heating of wine at 145 ° F (62.7°C) for 30 min to destroy souring bacteria. 1895 Harry Russell showed that gaseous swelling with bad odors in canned peas was due to growth of heat-resistant bacteria (spores 1820 Justin Kerner described food poisoning from eating blood sausage (due to botulism). Fatal disease from eating blood sausage was recognized as early as A.D. 900. 1849 John Snow suggested the spread of cholera through drinking water contaminated with sewage 1884 Robert Koch in , which was isolated in pure form 1854 Filippo Facini named the cholera bacilli as Vibrio cholera 1856 William Budd 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 1800 G. de Morveau and advocated the use of chlorine to sanitize potable water. W. Cruikshank 1885 Theodor Escherich isolated Bacterium coli (later named Escherichia coli) from the feaces and suggested that some strains were associated with infant diarrhea 1888 A.A. Gartner isolated Bacterium (later Salmonella) enteritidis from the organs of a diseased man as well as from the meat the man ate. 1896 Marie von Ermengem proved that Salmonella enteritidis caused a fatal disease in humans who consumed contaminated sausage. 1894 J. Denys associated pyogenic Staphylococcus with death of a person who ate meat prepared from a diseased cow. 1895 Marie von Ermengem isolated Bacillus botulinus (Clostridium botulinum) from contaminated meat and proved that it caused botulism 1854 Heinrich Schröder and Theodore von Dusch used cotton to close tubes and flasks to prevent microbial contamination in heated culture broths. 1876 Car Weigert used methylene blue (a synthetic dye) to stain bacteria in aqueous suspension 1877 Ferdinand Cohn showed heat resistance of Bacillus subtilis endospores. 1878 Joseph Lister isolated Streptococcus (now Lactococcus) lactis in pure culture by serial dilution from sour milk 1880 Robert Koch and his introduced many important methods that are used in all branches of associates microbiology, such as solid media (first gelatin, then agar) to purify and enumerate bacteria, Petri dish, flagellar staining, steam sterilization of media above 100 C, and photography of cells and spores. 1884 Hans Christian Gram developed Gram staining of bacterial cells.