MICROBIOLOGY What is microbiology Study of Microorganisms Organisms
MICROBIOLOGY
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 (Pseudomonas aeruginosa) 5. EVOLUTION (antibiotic resistance, pathogens)
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
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)
Phylogenetic classification of microorganisms (new school) Prokaryotic Eubacteria Archaeabacteria Universal Ancestor Eukaryotic 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, p. H 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
Eucaryotes vs Procaryotes
Eucaryotes True nucleus – nuclear membrane – more than 1 chromosome – chromosome replicated by mitosis – membrane-bound organelles ex. algae, fungi, protozoa, plants, animals
Eucaryotic Cell
Procaryotes Nuclear area (nucleoid) – no nuclear membrane – 1 chromosome – no mitosis – ribosomes are the only membranebound organelles ex. bacteria (rickettsia, blue-green algae), archaea
Procaryotic Cell
Major Groups of Microorganisms Algae Fungi Protozoa Bacteria Archaea Viruses
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
Branches of Microbiology • Bacteriology: study of bacteria • Mycology: study of fungi • Immunology: study of immunity – Edward Jenner, UK: developed vaccination (1798) – Metchnikoff, RU: discovered phagocytes (1884) – Paul Ehrlich, DE: theory of immunity (1890) • Virology: study of viruses – Beijerinck, NE: discovered intracellular reproduction of TMV; coined the term “virus” (1899)
Branches of Microbiology • Parasitology: study of protozoa and parasitic • worms Chemotherapy – – Treatment of disease by using chemical means Antibiotics produced naturally Synthetic drugs Paul Ehrlich (1878) – used arsenic compounds to fight disease – ‘magic bullet’ – Alexander Fleming, Scotland (1928) discovered penicillin – Selman Waksman, Ukraine (1944) discovered streptomycin • Problems – Toxicity of drugs => Selective toxicity – Resistance of bacteria to drugs
Branches of Microbiology • Recombinant DNA Technology – – – Recombinant DNA Genetic engineering/biotechnology Microbial genetics – mechanism by which microbes inherit genes – Molecular biology – structure and function (expression) of genes – Molecular epidemiology/diagnostics • Biotechnology – GMOs/GEMs for industrial, pharmaceutical and agricultural applications – Improvements of agriculture (plants and animals) – Gene therapy: inserting a missing gene or replacing a defective one in human cells.
18 20 th Century Microbiology • Molecular biology • Use of microbes as model systems for study • Study of DNA, proteins synthesis • Tools and processes for recombinant DNA • Applied microbiology • Food industry • Water and sewage treatment • Bioremediation • Medicine – Emerging diseases; antibiotic resistance
Use of Microorganisms in environment 1. Fixation of atmospheric nitrogen 2. Decomposition of organic wastes and residues 3. Suppression of soil-borne pathogens 4. Recycling and increased availability of plant nutrients 5. Degradation of toxicants including pesticides 6. Production of antibiotics and other bioactive compounds 7. Production of simple organic molecules for plant uptake 8. Complexation of heavy metals to limit plant uptake 9. Solubilization of insoluble nutrient sources 10. Production of polysaccharides to improve soil aggregation.
The role of Microorganism (Benefits): • Maintain balance of environment (microbial ecology) • Basis of food chain • Nitrogen fixation • Photosynthesis • Digestion, synthesis of vitamins • Manufacture of food and drink
The role of Microorganism (Benefits): • Genetic engineering • Synthesis of chemical products • Recycling sewage • Bioremediation: use microbes to remove toxins (oil spills) • Use of microbes to control crop pests • Normal microbiota (probiotic)
Industrial Microbiology • Important field within the microbiological sciences • Industrial microbiology used in various applications – Microbes in fermentation – Microbes in the production of several industrial products – Treatment of water and wastewaters – Disposal and cleanup of biological wastes – Treatment of mine drainage
Industrial Microbiology • Industrial Products of Microorganisms – Enzymes and other industrial products • Microbial products used as food additives and supplements • Include vitamins, amino acids, organic acids, dyes – Alternative fuels • Some microbes produce carbohydrates used as fuels • Other microbes convert biomass into renewable fuels – Pharmaceuticals • Includes antimicrobials, recombinant hormones, and other cell regulators
Industrial Microbiology • Industrial Products of Microorganisms – Pesticides and agricultural products • Microbes used to help crop management – Biosensors and bioreporters • Use of microorganisms to solve environmental problems • Biosensors – Bacteria or microbial products combined with electronic measuring devices • Bioreporters – Composed of microbes with innate signaling capabilities
Industrial Microbiology • Water Treatment – Water pollution • Water pollution can occur three ways – Physically v Presence of particulate matter – Chemically v Presence of inorganic or organic compounds – Biologically v Too many or non-native microorganisms • Polluted waters support a greater than normal microbial load
Industrial Microbiology • Water Treatment – Treatment of drinking water • Potable water is water considered safe to drink – Water is not devoid of microorganisms and chemicals v Levels are low enough that it is not a health concern • Presence of coliforms in water indicates fecal contamination – Increased likelihood disease-causing microbes present • Treatment of drinking water involves four stages
Industrial Microbiology • Water Treatment – Water quality testing • Majority of waterborne illnesses caused by fecally contaminated water • Indicator organisms signal possible presence of pathogens – E. coli or other coliforms used as indicator organisms – E. coli is a good indicator organism v Consistently found in human waste v Survives in water as long as most pathogens v Easily detected by simple tests
Industrial Microbiology • Water Treatment – Treatment of wastewater • Wastewater (sewage) – Water that leaves homes or businesses after use • Wastewater contains a variety of contaminants • Treatment intended to remove or reduce contaminants • Processed to reduce the biochemical oxygen demand (BOD) – Oxygen needed by aerobic bacteria to metabolize wastes in water – Levels reduced so unable to support microbial growth
Environmental Microbiology • Bioremediation – Uses organisms to clean up toxic, hazardous, or recalcitrant compounds by degrading them to harmless compounds – Most known application is use of bacteria to clean oil spills
Bioremediation • Bioremediation is the use of bacteria (or fungi) to clean up hazardous environmental wastes. • The bacteria essentially turn the dangerous waste products into less hazardous, easy to dispose of, waste. • Plants are also being tested in some areas to do this job (Sunflowers at Chernobyl removed Cesium and Strontium).
Biofuels • A biofuel is a plant derived fuel that is deemed more environmentally friendly that current fuel sources as they all release less carbon dioxide into the atmosphere. • Ethanol from corn is placed in many gasoline varieties in North America. • Biodiesel is fuel made from used cooking oil. • Biogas is made from gases released by compost or a landfill.
• The current project of many biofuel scientists is aptly nicknamed “A Journey to Forever”, creating a self-sustaining biofuel cell that gives off no greenhouse gas emissions. • Many different bacterial strains can produce lots of hydrogen under anaerobic conditions. • This hydrogen can be used as a fuel source with the only waste product being oxidized hydrogen… water. • This technology has not been perfected yet. Biofuels
Environmental Microbiology • Role of Microorganisms in Biogeochemical Cycles – Biogeochemical cycles • Processes by which organisms convert elements from one form to another • Elements often converted between oxidized and reduced forms • Involve the recycling of elements by organisms
Environmental Microbiology • Role of Microorganisms in Biogeochemical Cycles – Biogeochemical cycling entails three processes • Production – Inorganic compounds converted into organic compounds • Consumption – Organisms feed on producers and other consumers • Decomposition – Conversion of organic compounds in dead organisms into inorganic compounds
Environmental Microbiology • Soil Microbiology – Examines the roles played by organisms living in soil – Nature of soils • Soil arises from the weathering of rocks • Soil also produced through the actions of microorganisms
Environmental Microbiology • Soil Microbiology – Microbial populations in soils • Microbial populations present in the soil – Bacteria are numerous and diverse inhabitants of soil – Archaea present but are difficult to culture and study – Fungi are also populous group of microorganisms – Algae and protozoa are also present in the soil • Microbes perform a number of functions – Cycle elements and convert them to usable form – Degrade dead organisms – Produce compounds with potential human uses
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