Microbes in our lives
- 1. Living things too small to be seen with the unaided eye are called microorganisms
- 2. Microorganisms are important in maintaining Earth's ecological balance.
- 3. Some microorganisms live in humans and other animals and are needed to maintain good health.
- 4. some microorganisms are used to produce foods and chemicals
- 5. some microorganisms cause disease.
Naming and classifying microorganisms
- 1. In a nomenclature system designed by Carolus Linnaeus(1735) each living organism is assigned two names.
- 2. The two names consist of a genus and a specific epithet, both of which are underlined or italicized.
Types of Microorganisms
- 1. Bacteria are unicellular organisms. because they have no nucleus, the cells are described as prokaryotic.
- 2. The three major basic shapes of bacteria are bacillus, coccus and spiral.
- 3. most bacteria have a peptidoglycan cell wall; they divide by binary fission, and they may possess flagella.
- 4. bacteria can use a wide range of chemical substances for their nutrition.
Types of microorganisms
- 1. Archaea consist of prokaryotic cells; they lack peptidoglycan in their cell walls
- 2. Archaea include methanogens, extreme halophiles, and extreme thermophiles
Types of Microorganisms
- 1. Fungi(mushrooms, molds, yeasts) have eukaryotic cells (cells with a true nucleus), most fungi are multicellular.
- 2. Fungi obtain nutrients by absorbing organic material from their environment.
Types of MIcroorganisms
- 1. Protozoa are unicellular eukaryotes.
- 2. protozoa obtain nourishment by absorption or ingestion through specialized structures
Types of Microorganisms
- 1. Algae are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis
- 2. algae produce oxygen and carbohydrates that are used by other organisms
types of microorganisms
- 1. Viruses are noncellular entities that are parasites of cells.
- 2. viruses consist of a nucleic acid core (DNA or RNA) surrounded by a protein coat. An envelope may surround the coat.
Types of microorganisms
Multicellular animal parasites
- 1. the principal groups of multicellular animal parasites are flatworms and roundworms, collectively called helminths.
- 2. The microscopic stages in the life cycle of helminths are identified by traditional microbiolgical procedures.
Classification of microorganisms
- 1. all organisms are classified into bacteria, archaea, and eukarya,
- Eukarya include protists, fungi, plants, animals.
The first observation
- 1. Robert Hooke observed that cork was composed of "little boxes" he introduced the term cell (1665)
- 2.Hooke's observation laid the groundwork for development of the cell theory; the concept that all living things are composed of cells.
- 3. Anton van Leeuwenhoek using a simple microscope was the first to observe microorganisms (1673)
The Debate over spontaneous Generation
- 1. Until the mid 1880s many people believed in spontaneous generation, the idea that living organisms could arise from nonliving matter.
- 2. Francesco Redi demonstrated that maggots appear on decaying meat only when flies are able to lay eggs on the meat (1668)
- 3. John Needham claimed that microorganisms could arise spontaneously from heated nutrient broth(1745)
- 4. Lazzaro Spallanzani repeated Needham's experiments and suggested that Needhams results were due to microorganisms in the air entering his broth (1765)
- 5. Rudolf Virchow introduced the concept of biogenesis; living cells can arise only from preexisting cells. (1858)
- 6. Louis Pasteur demonstrated that microorganisms are in the air everywhere and offered proof of biogenesis (1861)
- 7. Paster's discoveries led to the development of aseptic techniques used in laboratory and medical procedures to prevent contamination by microorganisms.
The Golden age of microbiology
1. The science of microbiology advanced between 1857- 1914
Fermentation and Pasteurization
- 1. Pasteur found that yeast ferment sugars to alcohol and that bacteria can oxidize the alcohol to acetic acid
- 2. A heating process called pasteurization is used to kill bacteria in some alcoholic beverages and milk
The Germ Theory of disease
- 1. Agostino Bassi (1835) and Pasteur (1865) showed a casual relationship between microorganisms and disease.
- 2. Joseph Lister introduced the use of a disinfectant to clean surgical wounds in order to control infections in humans (1860)
- 3. Robert Koch proved that microorganisms cause disease. He used a sequence of procedures, now called Koch's postulates (1876), that are used today to prove that a particular microorganisms causes a particular disease.
- 1. IN a vaccination, immunity (resistance to a particular disease) is conferred by inoculation with a vaccine.
- 2. IN 1798, Edward Jenner demonstrated that inoculation with cowpox material provides humans with immunity to small pox.
- 3. About 1880 Pasteur discovered that avirulent bacteria could be used as vaccine for fowl chlolera; he coined the word vaccine
- 4. Modern vaccines are prepared from living avirulent microorganisms or killed pathogens, from isolated components of pathogens, and by recombinant DNA techniques.
The Birth of Modern Chemotherapy; Dreams of a "Magic Bullet"
- 1. Chemotherapy is the chemical treatment of a disease.
- 2. Two types of chemotherapeutic agents are synthetic drugs( chemically prepared in the laboratory) and antibiotics (substances produced naturally by bacteria and fungi to inhibit the growth of other microorganisms.
- 3. Paul ehrlich introduced an arsenic containing chemical called salvarsan to treat syphilis (1910)
- 4. Alexander Flemingobserved that the penicillium fungus inhibited the growth of a bacterial culture. He bamed the active ingredient penicillin (1928)
- 5. Penicillin has been used clinically as ba antibiotic since the 1940s.
- 6 Researchers are tackling the problem of drug resistant microbes.
Modern Developments in MIcrobiology
- 1. Bacteriolgoy is the study of bacteria, mycology is the study of fungi, an dparasitology is the study of parasitic protozoa and worms
- 2. Microbiologists are using genomics, the study of all of an organism's genes, to classify bacteria, fungi and protozoa
- 3. The study of AIds analysis of the action of interferons, and the development of new vaccines are among the current research interests in immunology.
- 4. new techniques in molecular biology and electron microscopy have provided tools for advancing our knowledge of virology
- 5. The development of recombinant DNA technology has helped advance all areas of microbiology.
Microbes and Human Welfare
- 1. Microorganisms degrade dead plants and animals and recycle chemical elements to be used by living plants and animals.
- 2. Bacteria are used to decompose organic matter in sewage.
- 3. Bioremediation processes use bacteria to clean up toxic wastes.
- 4. Bacteria that cause diseases in insects are being used as biological controls of insect pests. Biological controls are specific for the pest and do notharm the environment
- 5. Using microbes to make products such as foods and chemicals is called biotechnology.
- 6. using recombinant DNA bacteria can produce improtant substances such as proteins, vaccines and enzymes.
- 7. in gene therapy, viruses are used to carry replacements for defective or missing genes into human cells.
- 8. Genetically modified bacteria are used in agriculture to protect plants from frost and insects to improve the shelf life of produce.
Microbes and Human Disease
- 1. everyone has microorganisms in and on the body; these make up the normal microbiota or flora
- 2. The sidease producing properties of a species of microbes and the host's resitance are imprtant factors in determingnwhether a person will contract a disease
- 3. Bacterial communities that formslimy layers on surfaces are called biofilms
- 4. An infections disease is one in which pathogens invade a susceptible host.
- 5. an emerging infectious disease (EID) is a new or changing disease showing an increase in incidence in the recent past or a potential to increase in the near future.
People came to believe that living organisms arise from nonliving matter because they would see flies coming out of manure and maggots coming out of dead animals. and see microorganisms appear in liquids after a day or two.
Biological control of pests
1. Certain microorganisms cause diseases in insects. Microorganisms that kill insects can be effective biological control agents because they are specific for the pest and do not persist in the environment/
Carbon, oxygen, nitrogen, sulfur, and phosphorus are required for all living organisms. microorganisms convert these elements into forms that are useful for other organisms. many bacteria decompose material and release carbon dioxide into the atmosphere that plants use. Some bacteria can take nitrogen from the atmosphere and convert it into a form that plants and other microorganisms can use.
organic matter in sewage is decomposed by bacteria into carbon dioxide, nitrates, phosphates, sulfate, and other inorganic compounds in a wastewater treatment plant.
human insulin production
Recombinant DNA technigues have resulted in insertion of the gene for insulin production tinto bacteria. These bacteria can produce human insulin inexpensively.
Microorganisms can be used as vaccines. some microbes can be genetically ehgineered to produce components of vaccines.
biofilms are aggregated baterial adhering to each other and to a solid surface
studies biodegradation of toxic wastes,
study the symptoms of AIDS
studies biodegradation of toxic wastes, study the life cycle of cryptosporidium
studies the production of human proteins by bacteria, develops gene therapy for a disease
studies the production of human proteins by bacteria, studies the production of toxin by e coli
studies the fungus candida albicans
studies the causative agent of ebola hemorrhagic fever
prokaryote without peptidoglycan cell wall
cell wall made of cellulose photosynthetic
cell wall made of peptidoglycan
cell wall made of chitin
unicellular complex cell structure lacking a cell wall
not composed of cells
Avery, MacLeod, and McCarty
proved that DNA is the hereditary material
Beadle and Tatum
showed that genes code for enzymes
spliced animal DNA to bacterial DNA
used the first synthetic chemotherapeutic agent
first to observe cells in plant material and name them
observed that viruses are filterable
Jacob and Monod
discovered how DNA controls protein synthesis in a cell
developed vaccine against smallpox
proved that microorganisms can cause disease
proposed a classification system for streptococci based on antigens in their cell walls
Lederberg and Tatum
discovered that DNA can be trasferred from one bacterium to another
first to use disinfectants in surgical procedures
disproved spontaneous generation
first to characterize a virus
first to observe bacteria
said living cells arise from preexisting living cells
used bacteria to produce acetone
WHy you would buy Bacillus thuringiensis
B. thuringiensis is sold as a biological insecticide
why you would buy saccharomyces
saccharomyces is the yeast sold for making bread, wine and beer.
The genus name of a bacterium is erwinia and specific epithet is amylovora. write the scientific name of this organism correctly. using this name as an example explain how scientific names are chosen.
character of bacteria
- 1. are prokaryotic
- 2. have peptidogycan cell walls
- 3. grow by binary fission
- 4. have ability to move
- 1. e-coli is part of the normal microbiota of humans.
- 2. e-coli is beneficial in human intestines.
- 3. a disease causing strain of E coli causes bloody diarrhea