Chapter 1. History and Scope of Microbiology PDF

CHAPTER 1 THE HISTORY AND SCOPE OF Scope of Microbiology MICROBIOLOGY History  What is Microbiology? The study of organisms that are too small to be clearly seen by unaided eye (microorganisms)  Title What is microorganism? Th...

CHAPTER 1 THE HISTORY AND SCOPE OF Scope of Microbiology MICROBIOLOGY History  What is Microbiology? The study of organisms that are too small to be clearly seen by unaided eye (microorganisms)  Title What is microorganism? The organisms that are too small to be clearly seen by naked eye Simple in construction, lack highly differentiated cells and distinct tissues Microorganisms include viruses, bacteria, protozoa, algae, and fungi Microorganisms are ubiquitous crowd pets toilet bedroo kitche m n  soil air tongue A simple experiment shows that microorganism are almost everywhere in our environment  Title Why study microbiology? Source of nutrients – Prochloroccocus, a cyanobacterium (blue- green algae): most abundant photosynthetic organism on Earth Animal digestion – capable of digesting high fiber material using microbial fermentation: cattle, sheep, goats Food/Beverages Industries – fermentation process (bread, ‘tempeh’ beer, Saccharomyces cerevisiae- yeast which made production chocolate and coffee) of bread and pizza possible Pharmaceuticals – antibiotics, vaccines, vitamins, enzymes Rhizopus oligosporus-fungus in the production of tempeh  Nutrient cycle – Microbial ecology: cycling of carbon, nitrogen Bioremediation – the use of microorganism metabolism to remove pollutants (degrade oil spill, remove toxic waste) – genetically engineered microbes Fundamental Biology – applicable to ecology, genetics, biochemistry etc. Microbial protein Alcanivorax borkumensis- ‘oil- eating bacteria’ which turns oil – Dried cells of microorganisms used as food or into bioplastics feed known as ‘single cell’ protein – Spirulina and Chlorella (single cell green algae) Important Discoveries in Microbiology Important Discoveries in Microbiology  Classification schemes Prokaryotic cells lack a true membrane- bound nucleus Eukaryotic (eu = true) cells have a membrane-enclosed nucleus, more complex and usually larger than prokaryotic cells  Classification Schemes 3 Domains: 1. Bacteria (true bacteria/eubacteria ) 2. Archaea 3. Eukarya (all eukaryotic organisms) Universal Phylogenetic Tree  CHAPTER 1 THE HISTORY AND SCOPE OF MICROBIOLOGY Scope of Microbiology History History of Microbiology  Discovery of Microorganisms Anton van Leeuwenhoek first person to observe microorganisms Anton van Leeuwenhoek (1632-1723) holding one of his microscopes Conflict over Spontaneous Generation Theory Spontaneous Generation – living organisms can develop from non-living matter Francesco Redi (1626-1697) – disproved spontaneous generation for large animals – showed that maggots on decaying meat came from fly eggs  Francesco Redi’s experiments refuting the spontaneous generation of maggots in meat  But could spontaneous generation be true for microorganisms? John Needham (1713-1781) – Microbes arose spontaneously in broth from a “life force” – His experiment: broth in flasks boiled cool down sealed – Results: broth became cloudy and contained microorganisms Broth was boiled to kill any existing living microorganisms After cooled down and sealed, the broth turned cloudy (growth) He claimed that microorganisms in broth developed independently of other cells There was a life force that produced spontaneous generation  Lazzaro Spallanzani (1729-1799) – Disproved theory of spontaneous generation – His experiment: broth in flasks sealed boiled – Results: no growth of microorganisms – Air (oxygen) is not present – air (oxygen) is a vital component Microorganisms did not arise spontaneously in the broth They came from pre-existing microbes in the air Arguments: Spallanzani's results might be due to the lack of "vital force" from air in the sealed flasks  Louis Pasteur (1822-1895) His experiments – placed broth in flasks – created flasks with long, curved necks – boiled the solutions – left flasks exposed to air Neck of flask allowed air to enter but prevented airborne particles (such as dust and microorganisms) from reaching the broth An actual “swan-necked” flask that Pasteur used in refuting the theory of spontaneous generation  Louis Pasteur (1822-1895) Results: No growth of microorganisms Broth in the flask remained free of microbial life eventhough air could enter  Louis Pasteur (1822-1895) However, if the flask was tilted, the broth could contact the trapped particles in the neck, leading to microbial growth Conclusion: microorganisms came from the environment and not from spontaneous generation Golden age of Microbiology (1857-1914) Many disease producing organisms discovered Microbial metabolism studies undertaken Microbiological techniques developed Better understanding of the role of immunity and ways to control and prevent infection by microbes  Relationship between Microorganisms and Joseph Lister Disease… – showed that microorganisms were the causal agents of disease – designed a system of surgery to prevent microorganisms from entering wounds – developed methods for treating instruments and surgical dressings Immunological Studies Edward Jenner (1798) – used a vaccination procedure to protect individuals from smallpox – Didn’t even know HOW his vaccination even worked Pasteur and his coworkers – developed vaccines for chicken cholera, anthrax, and rabies Small pox For many centuries, smallpox devastated mankind. In modern times we do not have to worry about it thanks to the remarkable work of Edward Jenner and later developments from his endeavors. With the rapid pace of vaccine development in recent decades, the historic origins of immunization are often forgotten.  Robert Koch (1843-1910) – established the relationship between Bacillus anthracis and anthrax. – Koch’s postulates to establish the link between a particular microorganism and a particular disease  Koch’s Postulates The microorganism must be present in every case of the disease but absent from healthy individuals The suspected microorganism must be isolated and grown in a pure culture The same disease must result when the isolated microorganism is inoculated into a healthy host The same microorganism must be isolated again from the diseased host Koch’s Postulates Bacillus anthracis and anthrax  Anthrax Bioterrorism Attacks- United States, 2001 Bacillus anthracis sent through U.S. mail 22 cases (inhalation and 11 cutaneous). Most exposures occurred in mail sorting facilities and sites where mail was opened.  Discovery of Agar in Microbiology Angelina Hesse developed the use of agar to grow microorganisms (the women who made microbiology possible) She was the wife of Walter Hesse who worked in Koch’s laboratory. Discovery of agar, Petri dish, nutrient agar. Angelina & Walther  Treatment of Disease Chemothera py – Antibiotics – Synthetics Alexander Fleming  Industrial Microbiology Louis Pasteur – alcohol fermentations were the result of microbial activity – developed the process of pasteurization to preserve wine during storage Development of Techniques for Studying Microbial Pathogens Charles Chamberland – discovered vaccine for chicken cholera (by accident) – developed porcelain bacterial filter – used to isolate first virus studied Chamberland filter  Microbiology Today Recombinant DNA Technology Bioinformatics Genomics and Proteomics Bacterial quorum sensing-cell to cell communication that allows bacteria to share information  Future of Microbiology Challenges and opportunities Significant shift from culture based lab practices to molecular approaches directly from environment-metagenomics Bacterial quorum sensing-role in virulence and controlling new infectious diseases Bioinformatics-combines elements of biology and computer science in understanding biological data  Metagenomics Metagenomics = the study of genetic material recovered directly from environmental samples Such work revealed that the vast majority of microbial biodiversity had been missed by cultivation-based methods