Microbiology

Introduction •  Aseptic area: area free from microorganism including virus also •  Asepsis: State of being free from microorganism •  Contamination: Undesired introduction of impurities of chemical or microbiological nature into the starting material, or intermediate or final product Importance of asepsis •  To prevent transmission of disease •  To avoid decomposition and spoilage of food and beverages •  To maintain pure culture characteristics •  To inhibit interference from contaminating microorganism Sources and prevention of contamination Various sources of contamination along with some of the important preventive measures are as under- 1.  Premises and design of building •  Entry of insects inside the manufacturing area should be eliminated •  Interior surface of wall, floor and ceiling should be smooth, free from crack and open joints •  Entry of unauthorized person should also be prevented 2....

• Microbiology is the study of – living organism of microscopic size ( bacteria, fungi, algae, protozoa ) and – infectious agent at borderline of life ( virus ) •  Louis Pasteur coined the term ( Father of Microbiology ) Scope of microbiology •  Microbes are attractive models for studying fundamental life process •  Nitrogen fixing microbes- can synthesize many proteins e.g. Cyanobacteria •  Can produce Vit . K and prevent colonization of other pathogenic bacteria inside body e.g. E. coli •  Commercial preparation of antibiotics e.g. penicilline from Penicillium chrysogenum , Macrolides from Streptomyces venezuela •  Commercial preparation of alcoholic beverages like beer, wine, from Saccharomyces •  Commercial preparation of food products like bread (Saccharomyces), cheese ( Arthrobacter ) , sausage ( Aspergillus ) etc •  Commercial preparation of enzymes like Lipase from Candida, Pectinase from Aspergillus etc...

Louis Pasteur (1822-1895) •  French chemist and microbiologist • He p roved the "theory of biogenesis" • Presented evidence for the "germ theory of fermentation" •  He heated the wine to 50–60 °C (120–140 °F), and p roposed  that removal of undesirable microbes by heating could lead to good ferment. This  process now known universally as pasteurization •  1865 , two parasitic diseases called pébrine and flacherie were killing great numbers of silkworms, which was causing a great loss to Silk Industries. Pasteur proved the cause, (i.e. microbe attacking silkworm eggs) •  Pasteur's first vaccine discovery was in 1879 , with a disease called chicken cholera • He extended his germ theory to develop causes and vaccinations for so many diseases such as anthrax, cholera, TB and smallpox •  In 1885 , He vaccinated a 9-year-old boy who had been bitten by a rabid dog ; and He got succeeded

Robert Koch (1843-1910) •  German physician •  He discovered the anthrax disease cycle (1876) and the bacteria responsible for tuberculosis (1882) and cholera (1883 ) •  Awarded Nobel Prize in 1905 •  Koch and his team also developed ways of staining bacteria to improve the bacteria’s visibility under the microscope •  Determined guidelines (which are widely accepted now as Koch's Postulates) to prove that- disease is caused by specific organism •  Koch’s postulates are: ü Specific microorganism is associated with a given disease ü Microorganism can be isolated from the diseased animal and grown in pure culture ü Cultured microbe will cause disease when transferred to a healthy animal ü Same type of microorganism can be isolated from the newly infected animal

Antony van Leeuwenhoek (1632-1723) q Father of Microbiology q Lived in Holland q Made more than 250 microscopes consisting of home ground lenses mounted in brass and silver; w ith magnification of about 200 to 300 times q First to report the  single-celled organisms with accurate descriptions and drawings ( “animalcules” ) q He had written 190 letters to the Society, centered around his work in microscopy q 1674 - D iscovered and described the alga Spirogyra , and various ciliated and flagellated protozoa q 1675 - Discovered and accurately described and differentiated erythrocytes in humans, swine, fish and birds q 1677 - First to observe spermatozoa in humans, dogs, swine, birds etc q 1679 and 1684 - Described the needle-shaped microscopic sodium urate crystals that formed in the gout patients q 1683 - O bserved bacteria in feces q 1683 - Found parasitic protozoa in feces ( Giardia sp. and Balantidium sp .) q 1702 - Observed the ciliate p...

History and Development of Microbiology } 1220-1292 ; Roger Bacon postulated – disease is produced by invisible living creatures } 1483-1553; Fracastoro also suggested the same } 1632-1723; Antony van Leeuwenhoek of Holland observed and described microbes accurately as animalcules } He constructed a simple microscope composed of double convex lens with magnification of 50-300 times } 1673; He sent a detailed letter about his findings to the Royal Society of London Spontaneous Generation Vs. Biogenesis } Spontaneous generation:  living organism could develop from non-living matter e.g. maggots could be produced by exposing meat to warmth and air } 1626-1697; Francesco Redi suggested that meat did not produce maggots spontaneously.  However,  flies, attracted towards meat, laid eggs producing maggots } In 1749, John Needham observed the appearance of bacteria in meat and again supported abiogenesis } 1729-1799; Lazaro Spallanzani boiled beef b...