What is microbiology Study of Micro-organisms: Organisms that EXIST as Single Cells or cell clusters and must be viewed individually with the aid of a Microscope 1. EXIST (Webster definition)To continue to be, have life; live HALLMARKS OF LIFE 1. METABOLISM (nutrient uptake, biomass, waste output) 2. DIFFERENTIATION (Bacillus spp. Caulobacter) 3. REPRODUCTION (binary fission) 4. COMMUNICATION 5. EVOLUTION (antibiotic resistance, pathogens) Metabolism Take in nutrients from the environment glucose, lactose, other sugars, fats=lipids, proteins, toxic wastes, oils and petrol Assimilate the nutrients into BIOMASS DNA, proteins, carbohydrates and complex carbohydrates, lipids Release waste products into the environment gases, alcohols, acids and organic compounds Differentiation— to form distinct structures Caulobacter spp. Vegetative cells versus stalk cells K.C. Keiler M. Dworkin Differentiation— to form distinct structures Bacillus spp. endospore forming cells Anabaena spp. Cyanobacteria forming heterocysts T.J. Deveridge M. Dworkin Reproduction To generate progeny of ones same type A bacterium duplicates its DNA and forms a daughter cell via binary fission Yeast duplicates its DNA and forms a daughter cell via budding, or mates with another yeast cell and produces haploid progeny. J. Pitocchelli E. Hettema Communication AMNH--NYC interaction with other cells—response to other cells Vibrio fischeri and Lantern fish Kolter and Losick Evolution To change ones genetic make up (DNA sequence) to adapt to ones environment Bacteria can take up DNA from the environment or other cells via Transformation—uptake of naked DNA Transduction—phage (bacterial specific virus) mediated uptake of DNA Conjugation—uptake of DNA that requires the interaction of two bacteria Antibiotic resistance, bacterial pathogenesis What is microbiology Study of Micro-organisms: Organisms that EXIST as Single Cells or cell clusters and must be viewed individually with the aid of a Microscope 2. KEYWORD single CELLS (OR cell clusters) CHARACTERISTICS THAT MICROORGANISMS HAVE THAT MAKE THEM TRUE CELLS 1. CELL MEMBRANE –barrier that separates the inside of the cell from the outside 2. NUCLEUS OR NUCLEIOD – location of genetic information (DNA) 3. CYTOPLASM –location of the machinery for cell growth and function 4. MACROMOLECULES – proteins, nucleic acids, lipids, polysaccharides 3. KEYWORD exist as SINGLE cells (OR cell clusters) We are multicellular creatures—made up of many cells What makes one of our cells different from a microbial cell?? A single microbial cell can have an independent existence—our specialized cells need to interact with other cells in order to carry out their cellular functions for the good of the entire organism. What organisms are considered to be microbial cells and studied in microbiology 1. 2. 3. 4. 5. BACTERIA FUNGI ALGAE PROTOZOA Viruses(although not a cellular entity but an intracellular pathogen) 6. Prions (a biochemical anomaly—misfolded proteins) 7. Helminths Worms (multicellular) Taxonomy The study of phylogenetic relationships between organisms (The sorting of all living things based on their related or differentiating features) KINGDOM the highest level in classification PHYLUM related classes CLASS related orders ORDER related families FAMILY related genera GENUS closely related species SPECIES organisms sharing a set of biological traits and reproducing only with their exact kind Further classifications especially with bacteria: Strain—organisms within a species varying in a given quality Type—organisms within a species varying immunologically Taxonomy::relatively easy to classify animals and plants based on their behaviour and appearance—old school Taxonomy::initially not easy to classify microorganisms based on their behaviour and appearance Advancements in DNA amplification and DNA sequencing has greatly helped The phylogenetic relationships between microorganisms can be determined by sequencing the 16S and 18S ribosomal RNA of the organisms in question (ribosomal RNA—structural RNA of the ribosome that plays a role in protein synthesis) Phylogenetic classification of microorganisms (new school) Eukaryotic Prokaryotic Eubacteria Archaeabacteria Universal Ancestor Algae Fungi Protozoa Phylogenetic classification of micro-organisms EUBACTERIA most abundant of the bacteria found in soil, water and animal digestive tracts ARCHAEACTERIA live in extreme conditions (temperature, pH etc) mostly anaerobic (unable to live in the presence of oxygen) EUKARYOTES algae: live in soil and water, contains chlorophyll for photosynthesis, has a cell wall fungi: yeast, molds. Lack chlorophyll and obtains energy from organic compounds in soil and water, has a cell wall protozoa: colorless, lacks a cell wall, ingests other organisms or organic particles Major Differences between prokaryotic and eukaryotic micro-organisms Prokaryotes 1. Nonmembrane bound nucleiod region 2. DNA-one circular molecule one chromosome 3. Haploid-One copy of a gene 4. Plasma membrane does not contain sterols 5. Reproduction—simple binary fission Eukaryotes 1. Membrane bound nucleus containing DNA 2. DNA-linear molecules arranged to form several chromosomes 3. Diploid-Two copies of a gene 4. Plasma membrane contains sterols 5. Reproduction—meiosis and mitosis 6. Presence of membrane bound organelles such as chloroplasts and mitochondria Why study Microbiology ?? Microbiology as a BASIC Science Bacteria and yeast are useful in studying molecular biology, biochemistry and genetics --reproduce rapidly --are genetically (DNA) and biochemically more simple than higher order organisms --working with bacteria and yeast for understanding life processes has no ethical ramifications Microbiology as an APPLIED Science Medicine—Vaccine development, production of antibiotics, production of important biological enzymes (insulin) Industry—Production of beer, wine, cheeses and yogurt Agriculture—maintenance of soil fertility/digestion in cattle Ecology—Bioremediation—microorganisms that degrade toxic waste materials
