MICROBIO LESSON 3

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.