Cultivation of Bacteria Flashcards
All chemicals required by microorganisms are raw materials for their metabolism and reproduction are called?
Nutrients
All such events used in biosynthesis and energy production is referred as?
Nutrition
Example of Micro-nutrients?
- Cobalt
- Copper
- Manganese
- Molybdenum
Example of Macro-nutrients?
- Oxygen
- Hydrogen
- Carbon
- Nitrogen
- Phosphorus
- Sulfur
Producers, photosynthetic, use CO2 and H2O, sunlight as energy, make their own food
Autotroph
Require performed food, digestive and absorptive, most microbes
Heterotroph
Capture protons in order to acquire energy
Phototrophs
Organisms which obtain their energy by oxidizing electron donor
Chemotrophs
Energy source is the oxidizing energy of chemical compounds
Chemotrophs
Energy source is mainly sunlight.
Phototrophs
Organisms that can use reduced inorganic compounds as electron donors
Lithotrophs
Organisms that can use organic compounds as electron donors
Organotrophs
These bacteria gain energy from light and use reduced inorganic compounds such as H2S as a source of electron.
Photo-lithotrophs
These bacteria gain energy from light and use organic compounds such as succinate as a source of electron.
Photo-organotrophs
These bacteria gain energy from reduced inorganic compounds such as NH3 as a source of electron.
Chemo-lithotrophs
These bacteria gain energy from organic compounds such as glucose and amino acid as a source of electron.
Chemo-organotrophs
Most important factor that determines the rate of microbial growth, multiplication, survival and death of all microorganisms.
Temperature
Rate of enzyme reaction increases with higher temperature.
Temperature
The lowest temperature at which organisms grow.
Minimum
Highest growth rate
Optimum
The highest temperature at which growth occurs
Maximum
- Able to grow at 0 degrees or lower but they grow best at higher temperatures.
- Extremophilic organisms that are capable of growth and reproduction in low temperatures.
Psychrophiles/cryophiles
Grows best in moderate temperatures
20-45
Mesophiles
Heat-loving microorganisms
Grows best at above 45 degrees
Thermophiles
Thrives in extremely hot environment
Hyperthermophiles
- Refers to the negative logarithm of Hydrogen ion concentration
pH
Grow between pH 0 and 5.5
Acidophiles
Grow between pH 5.5 to 8.0
Neutrophiles
Grow between pH 8 to 14
Alkalophiles
- Organisms that can survive and grow in an oxygenated environment.
- Standard air atmosphere
AEROBES
- Microorganisms which may be poisoned by oxygen.
- DO NOT USE OXYGEN
- cannot grow in an air atmosphere
Anaerobes
It can tolerate low concentrations of oxygen
Tolerant Anaerobes
Killed by brief exposure of oxygen
Strict Anaerobes
- Anaerobic bacteria that do not require oxygen for growth although may use it for energy production if available.
Facultative Anaerobes
Under anaerobic conditions they may obtain energy by a metabolic process called?
Fermentation
- Can use oxygen
- Cannot withstand the level of oxygen present in the air (21%) and usually grow best at oxygen levels between 1-15%.
Microaerophiles
Pressure exerted on the cells by the movement of water resting on top of them.
Hydrostatic pressure
A method of multiplying microorganisms by letting them grow and reproduce in artificial culture media under controlled laboratory conditions or set-up.
Bacterial Cultivation
A nutrient material prepared for the growth of microorganisms in a lab.
Culture medium
When microbes are introduced into a culture medium to initiate growth.
Inoculum
The microbes that grow and multiply in or on a culture medium.
Culture
Main purposes of bacterial cultivation?
- To grow and isolate
- Infection and contaminants or colonizers
- Identification and characterization
Always used to prepare culture media
Distilled water
Prepared from a variety of seaweeds and is now universally used for preparing solid media.
Agar
The important constituents are peptones, proteases, amino acids, a variety of inorganic salts including phosphates, potassium and magnesium, and a certain accessory growth factors such as nicotinic acid and riboflavin.
Peptone
It contains a wide range of amino acids, growth factors and inorganic salts. It is used mainly as a comprehensive source of growth factors and may be substituted for meat extract in culture media.
Yeast extract
It contains mainly maltose, starch, dextrins and glucose, and contains about 5% of proteins and protein breakdown products, and a wide range of mineral salts and growth factors.
Malt extract
These are used for enriching culture media. Either human or animal blood can be used.
Blood and serum
It contains peptone and NaCl as major ingredients
Liquid media
It can be prepared by adding agar into liquid media
Solid Media
It is useful for the cultivation of microaerophilic bacteria for determination of bacterial motility.
Semi-solid media
It contains only basic nutrients for the growth of ordinary organisms and used as a general purpose media.
Simple media
- one common ingredient is peptone
- contain a variety of ingredients
Complex Media
- prepared exclusively from pure chemical substances and their exact composition is known.
Synthetic or Chemically-defined Media
- Simplest and most common medium in diagnostic laboratories
Basal media
-Prepared to meet nutritional requirements of bacteria by the addition of substance like blood, chocolate, or serum to a basal medium.
Enriched media
Used for isolation of streptococci, pneumococci and Hemophilus
Blood agar
It is used for isolation of Neisseria
Chocolate Agar
For isolation of Bordetella
Bordet-Gengou agar
It is used for the isolation of Corynebacterium diptheriae
Loeffler’s serum slope
It is used for the cultivation of Mycobacterium tuberculosis and Corynebacterium diptheriae
Dorset’s egg medium
- Prepared to meet nutritional requirements of bacteria by additional of substance like blood, chocolate, egg or serum to a basal medium.
Enriched media
- When a substance is added to a liquid medium which inhibits the growth of unwanted bacteria and favors the growth of wanted bacteria.
Enrichment Media
- When a substance is added to a solid medium which inhibits the growth of unwanted bacteria but favors the growth of wanted bacteria.
Selective Media
It contain certain reagents or supplements which when incorporated into culture media may allow differentiation of various kinds of bacteria.
Differential Media
This media contain an indicator which changes color.
Indicator media
- A holding medium designed to preserve the viability of microorganisms in the specimen but not allow multiplication.
Transport Media
These media are used to grow anaerobic organisms and contain reducing substances.
Anaerobic Media
This method is routinely employed for the isolation of bacteria in pure culture from clinical specimens.
Quadrant Streak Plate Method
Prepared by flooding the surface of the plate with a liquid culture or suspension of the bacterium, pipetting off the excess inoculum and incubating the plate.
Lawn Culture Method
Made in tubes containing agar slope or slant. Slopes are seeded by lightly smearing the surface of agar with loop in a zigzag pattern taking care not to cut the agar.
Stroke culture method
Glucose agar is punctured with a long, straight, charged wire into the center of the medium and withdrawing it in the same line to avoid splitting the medium.
Stab Culture Method
For cultivation of aerobes the incubation is done in an incubator under normal atmospheric condition.
Aerobic condition
It requires incubation without oxygen and differ in their requirement and sensitivity to oxygen.
Anaerobic Culture
Anaerobiosis can be achieved by:
- Production of vacuum
- Displacement of oxygen by other gases
- By absorption of oxygen by chemical or biological methods
- By displacement and combustion of oxygen
- By reducing agents
- Other anaerobic culture systems
