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GENERAL MICROBIOLOGY Introduction to Microbiology and Classification Characters of Microorganisms INTRODUCTION TO MICROBIOLOGY Microbiology(micros bios logos – small, live, study) study microorganisms and their activities. Microbiology is the study of microorganisms usually les...
GENERAL MICROBIOLOGY Introduction to Microbiology and Classification Characters of Microorganisms INTRODUCTION TO MICROBIOLOGY Microbiology(micros bios logos – small, live, study) study microorganisms and their activities. Microbiology is the study of microorganisms usually less than 1mm in diameter which requires some form of magnification to be seen clearly. Microbiology- study the organisms that can exist as single cells, contain a nucleic acid genome for at least some part of their life cycle, and are capable of replicating that genome themselves or getting replicated with the help of host cells. * Bacteria, fungi, protozoa, algae, viruses are examples.* Some are pathogenic "germ"; refers to a rapidly growing cell. MICROBES Pathogen or pathogenic-capable of producing disease. Though only a minority of microorganisms are pathogenic, practical knowledge of microbes is necessary for their treatment so is highly relevant to medicine and related health sciences. Normal flora [normal microbiota]- not typically-disease-causing microorganisms normally found in and on healthy individuals. on the skin, in the eyes, in the nose, in the mouth, in the upper throat, in the lower urethra, in the lower intestine. The Bacterium Escherichia coli; a photosynthetic cyanobacterium a fungus Ebola virus the malaria parasite (a protozoan CLASSIFICATION OF LIFE For many years, living organisms were divided into two kingdoms: Animalia(animal) and Plantae(vegetable). Classification Schemes Two kingdoms Plantae and Animalia But after 1800s, scientists realized that these two kingdoms could not adequately express the diversity of life. Since the 1960s, the most widely used scheme - five kingdoms. Viruses are separate group of biological entities, although not organisms in the same sense as Eukaryotes, Archaea and Bacteria. Classification schemes, 5 kingdoms plantae, Monera, Protista,, fungi, animalia prokaryotes domain bacteria (eubacteria) domain archaea (archaebacteria) eukaryotes Classification of Life 3 major Domains of life Bacteria Archaea Eukaryota (Eukarya) The first two are Prokaryotes (Bacteria and Archaea)- without true nucleus, while the Eukaryotes all have a true nucleus in each cell. The 3 Domains. Kingdom Monera All organisms in the Kingdom Monera are prokaryotes. lack nuclei and organelles most of their cell walls are made of peptidoglycan (the exceptions are the archaebacteria). The archaebacteria have cell walls that lack peptidoglycan, cell membranes that utilize different lipids, and ribosomes similar to those found in eukaryotes. The bacteria(eubacteria-true bacteria)are characterized by how they metabolize resources, their means of motility, and their shape. Most organisms in the kingdom Monera reproduce through binary fission (asexual) or conjugation (sexual). Taxonomy Taxonomy is the classification of organisms. The most common system in use today is the Five Kingdoms: Monera (Prokaryota), Protista, Fungi, Plantae, and Animalia. Organisms in each kingdom are divided into phyla. In each phylum, organisms are separated into classes. In each class, organisms are segregated into orders. In each order, organisms are divided into families. In each family, organisms are separated by genus. And finally, in each genus organisms are divided into species. Naming microorganisms binomial (scientific) nomenclature gives each microbe 2 names genus - noun, always capitalized and may be abbreviated species - adjective, lowercase, never abbreviated A genus name may be used alone to indicate a genus group; a species name is never used alone eg: Bacillus subtilis B. subtilis Both italicized or underlined Staphylococcus aureus (S. aureus) Bacillus subtilis (B. subtilis) Escherichia coli (E. coli) Nomenclature Common or descriptive names (trivial names) Names for organisms that may be in common usage, but are not taxonomic names eg: tubercle bacillus (Mycobacterium tuberculosis) meningococcus (Neiserria meningitidis) Group A streptococcus (Streptococcus pyogenes) Eukaryotes Prokaryotes kingdom - Monera domain - bacteria phylum– proteobacteria class– gammaproteobacterial order– enterobacterial family– Enterobacteriaceae genus– Escherichia species– Escherichia coli "The role of the infinitely small in nature is infinitely large" Louis Pasteur Historical Perspectives Historical Pioneers of Microbiology Robert Hooke, UK (1665) Proposed the Cell Theory Observed cork with crude microscope All living things are composed of cells Spontaneous generation Some forms of life could arise spontaneously from non-living matter Francesco Redi, IT (1668) Redi’s experiments first to disproved S.G. Antonie van Leeuwen Hoek First to observe living microbes His single-lens magnified up to 300X (1632-1723) Louis Pasteur French chemist Father/Founder of Modern Microbiology Fermentation – a microbiological process Beer/Wine not produced without microbes Showed microbes caused fermentation & spoilage Disproved spontaneous generation of m.o. Developed aseptic techniques. Developed a rabies vaccine. (1822-1895) Louis Pasteur 1822-95 Methods & Techniques of cultivation Introduced sterilization Tantalization (Tyndal-1877) Studied Silkworm disease, anthrax, chicken cholera, hydrophobia. Introduced live vaccines – Jenner (Cow-pox vaccine) Antirabbit vaccine Pasteur Institutes Joseph Lister 1867 Prof of Surgery, Glasgow Royal Informatory Introduced Antiseptic Surgery Called Father of Antiseptic Surgery BRANCHES OF MICROBIOLOGY Bacteriology: study of bacteria Mycology: study of fungi Virology: study of viruses Beijerinck, NE: discovered intracellular reproduction of TMV; coined the term “virus” (1899) Parasitology: study of protozoa and parasitic worms MICROBES MICROBES includes all those living organisms that cannot be viewed (seen) in any detail by the human eye. Alternatively, a MICROBE is any living creature that must be examined with a magnifying lens in order to see its unique physical characteristics (size, shape, motility, color). Introduction to Kingdoms and Domains The Six Kingdoms of Life Biologists have long organized living things into large groups called kingdoms. For example, a hummingbird, an earthworm, an elephant, and a butterfly are all members of the animal kingdom. But what is an animal? Given the diversity of living things, it is easy to forget that all living things have much in common. Focusing on a few fundamental characteristics makes it easier to see the related ness within kingdoms Cell Type Organisms are either prokaryotes, which have prokaryotic cells, or eukaryotes, which have eukaryotic cells. Scientists generally recognize two kingdoms of prokaryotes and four kingdoms of eukaryotes. Cell Walls The cells of the organisms in four kingdoms have a cell wall, which may be composed of different materials. The cells of the organisms in one kingdom do not have a cell wall. Body type organisms are either unicellular or multicellular. Two kingdoms consist only of unicellular organisms. Two other kingdoms have both unicellular and multicellular organisms. The two remaining kingdoms consist entirely of multicellular organisms, many of which have tissues and organs
