Untitled Flashcards Set

Microbial Nutrition - Substances required for microbial biosynthesis and energy. Nutrients - Raw materials necessary for microbial growth. Growth Requirements - Factors needed for microorganisms to grow. Physical Requirements - Environmental conditions affecting microbial growth. Chemical Requirements - Essential elements for microbial metabolism. Temperature - Optimal heat range for microbial growth. Psychrophiles - Microbes thriving at cold temperatures, 0-15°C. Psychrotrophs - Cold-loving organisms growing at 20-30°C. Mesophiles - Moderate temperature microbes, optimal at 25-40°C. Thermophiles - Heat-loving microbes, grow at 50-60°C. Hyperthermophiles - Microbes thriving at extreme temperatures, 80°C+. Incubation Temperature - Temperature settings for optimal microbial growth. Minimum Growth Temperature - Lowest temperature for microbial growth. Optimum Growth Temperature - Best temperature for species growth. Maximum Growth Temperature - Highest temperature for microbial survival. pH - Measure of acidity or alkalinity in solutions. Acidophiles - Bacteria thriving in acidic environments. Saccharomyces cerevisiae - Yeast species growing well at pH 5-6. Chemical Buffers - Substances used to stabilize pH in media. Osmotic Pressure - Pressure from dissolved molecules in a solution. Plasmolysis - Cell shrinkage due to high osmotic pressure. Halophiles - Microorganisms requiring high salt concentrations. Diatoms - Unicellular algae important in oceanic food chains. Dinoflagellates - Salt-tolerant algae, key in marine ecosystems. Hypertonic Solution - Solution with higher solute concentration than cell. Nutrient Acquisition - Process of obtaining nutrients from the environment. Trace Elements - Micronutrients essential for microbial growth. Oxygen - Gas required by many microorganisms for respiration. Halophiles - Microorganisms requiring high salt concentrations for growth. Obligate Halophiles - Require high salt concentrations to survive. Facultative Halophiles - Can grow in 2-5% salt concentration. Nutrient - Substance that promotes growth and repairs organisms. Water - Essential for microbial growth, comprising 80-90% of microbes. Carbon - Structural backbone of living matter, sourced from CO2 or organic materials. Autotrophs - Organisms using CO2 as their carbon source. Heterotrophs - Organisms using organic compounds for carbon. Photoautotroph - Uses light for energy and CO2 for carbon. Photoheterotroph - Uses light for energy and organic compounds for carbon. Chemoautotroph - Uses inorganic compounds for energy and CO2 for carbon. Chemoheterotroph - Uses organic compounds for energy and carbon. Capnophilic - Requires a carbon dioxide-rich environment for growth. Oxygen - Final electron acceptor for aerobic bacteria during respiration. Aerobic Organisms - Require oxygen for energy-yielding growth. Anaerobic Organisms - Grow without oxygen; include obligate and facultative types. Facultative Anaerobes - Grow in presence or absence of oxygen. Obligate Anaerobes - Cannot tolerate oxygen; harmed by reactive oxygen species. Aerotolerant Anaerobes - Can survive in oxygen but do not use it. Microaerophiles - Require low levels of oxygen for growth. E. coli - Example of facultative anaerobe; grows with or without oxygen. Clostridium - Example of obligate anaerobe; harmed by oxygen. Bacteriodes - Obligate anaerobes; do not tolerate oxygen. Fusobacterium - Example of obligate anaerobes; oxygen intolerant. Methanococcus - Obligate anaerobe; does not utilize oxygen. Reactive Oxygen Species (ROS) - Harmful oxygen derivatives; toxic to obligate anaerobes. Diatoms - Unicellular algae; part of oceanic food chains. Dinoflagellates - Unicellular algae; contribute to marine ecosystems. Protozoa - Single-celled organisms; diverse ecological roles. Fungi - Eukaryotic organisms; decomposers in ecosystems. Aerotolerant anaerobes - Bacteria that tolerate oxygen but cannot use it. Microaerophilic - Bacteria growing in low oxygen concentrations (2-10%). Nitrogen-fixing bacteria - Bacteria that obtain nitrogen from the atmosphere. Rhizobium - A nitrogen-fixing bacterium found in soil. Azotobacter - Another nitrogen-fixing bacterium in soil. Sulfur - Essential for protein synthesis in bacteria. Phosphorus - Key element for nucleic acid and phospholipid synthesis. Trace elements - Copper, iron, molybdenum, zinc for enzyme synthesis. Organic growth factors - Vitamins and amino acids required by some bacteria. Fastidious bacteria - Bacteria with complex nutrient requirements. Escherichia coli - Can synthesize all 20 amino acids from intermediates. Culture medium - Nutrient environment for microbial growth in labs. Pure culture - Culture with only one type of organism present. Mixed culture - Culture with multiple different organisms present. Sterile medium - Medium free of all forms of life before inoculation. Nutrient broth - Liquid medium containing proteins, salts, growth enhancers. Agar - Polysaccharide used to solidify culture media. Nutrient agar - Solid medium made with nutrient broth and agar. Potato dextrose agar - Medium for fungi requiring extra carbohydrates. Inoculum - Microbes introduced into culture media. Liquid medium - Prepared and autoclaved for microbial cultivation. Solid medium - Sterilized and dispensed for microbial growth. Cotton plugs - Cover test tubes to allow oxygen for aerobic bacteria. Synthetic media - Chemically defined medium with known exact composition. Defined medium - Used for research or culturing autotrophic bacteria. Contamination risk - Possibility of unwanted microbes in culture media. Anaerobic atmosphere - Oxygen-free environment required for anaerobic microorganisms. Fungi growth requirements - Extra carbohydrates and acidic environment for optimal growth. Rickettsiae and viruses - Require living tissue cells for best cultivation. Simple media - Contains carbon dioxide, nitrate, and minerals. Complex media - Nutrients from yeast, meat, or plant extracts. Peptones - Protein digests providing amino acids and peptides. Nutrient broth - Liquid medium supporting non-fastidious bacteria. Nutrient agar - Solid medium for culturing various microorganisms. Trypticase soy broth - Complex medium for diverse microbial growth. MacConkey agar - Selective for gram-negative bacteria, differentiates lactose fermentation. Solid media - Contains 1.5-2% agar for solidification. Semi-solid media - Contains 0.5% agar for partial solidification. Enrichment culture media - Supports fastidious microbes with added nutrients. Brain heart infusion - Enrichment medium for cultivating fastidious bacteria. Selective culture media - Suppresses unwanted bacteria, promotes desired microbes. Bile salts - Inhibit gram-positive bacteria, favor gram-negative growth. Sodium azide - Selective for gram-positive bacteria in culture media. Mannitol Salt Agar - Selective for halophilic and gram-positive bacteria. Sabouraud's dextrose agar - Isolates fungi, has a pH of 5.6. Differential culture media - Distinguishes between different bacterial groups. Blood agar - Enriched medium, differentiates hemolytic bacteria. Alpha-hemolytic - Produces greenish zone of hemolysis on blood agar. Beta-hemolytic - Produces clear zone of hemolysis on blood agar. Gamma-hemolytic - No zone of inhibition on blood agar. Lactose fermentation - Differentiates lactose fermenters from non-fermenters. Anaerobic growth media - Contains reducing agents to eliminate oxygen. Sodium thioglycolate - Chemical that removes oxygen for anaerobic cultures. Anaerobic jar - Used to grow anaerobic bacteria in plates. Capnophiles - Microbes that thrive in increased CO2 environments. Special culture techniques - Methods for culturing hard-to-grow organisms. Gonorrheae - A sexually transmitted infection caused by Neisseria gonorrhoeae. Streptococcus pyogenes - Bacteria causing strep throat and skin infections. Mycobacterium leprae - Bacteria causing leprosy, cultured in armadillos. Streak plate method - Technique to isolate bacteria on agar surface. Pour plate method - Dilution technique to isolate bacteria in agar. Microbial growth - Increase in microbial population over time. Reproduction patterns - Microorganisms reproduce, increasing population dramatically. Mitosis - Asexual reproduction involving nucleus duplication. Cytokinesis - Process where cell splits after mitosis. Sexual reproduction - Involves fusion of haploid nuclei to form diploid. Asexual reproduction - Reproduction without genetic exchange, like binary fission. Binary fission - Bacterial reproduction by DNA duplication and cell division. Generation time - Time for microbial population to double in numbers. Escherichia coli - Bacterium with a generation time of about 20 minutes. Logarithmic scale - Used to graphically represent large microbial populations. Growth curve - Graph showing bacterial population phases over time. Lag phase - Initial phase where bacteria acclimate to environment. Log phase - Exponential growth phase with rapid population doubling. Stationary phase - Population plateau due to balanced reproduction and death. Decline phase - Rapid die-off of bacteria, population decreases. Nutrient agar - Common medium for culturing bacteria. Petri dish - Container used for culturing microorganisms. Incubation - Process of maintaining optimal conditions for microbial growth. Metabolic activity - Biochemical processes occurring within microorganisms. Antimicrobial agents - Substances that inhibit microbial growth. Waste accumulation - Build-up of byproducts affecting bacterial survival. Environmental conditions - Factors influencing microbial growth and survival. Cell wall - Structure providing shape and protection to bacteria. Chromosomal DNA - Genetic material that duplicates during bacterial reproduction. Unicellular algae - Single-celled photosynthetic organisms. Protozoa - Single-celled eukaryotic organisms, often motile. Dilution - Process of reducing concentration of bacteria in a sample. Hardening - Process of agar solidifying after pouring. Colony - Visible mass of microorganisms grown on a medium.