Factors Influencing Growth Of Microorganism

Two factors:
1. Physical.
2. Chemical.

Physical factors that influencing growth of microorganism are such as:
1. Temperature.
2. pH.
3. Osmotic pressure.

TEMPERATURE
The temperature ranges over which an organism grows best are determined by enzymes present within the organism.
The optimum temperature for microorganism to function is ranging from 25 degree celcius to 40 degree celcius.
Optimum temperature for many pathogenic is 37 degree celcius.
There are 3 groups of microorganism that function optimally according to different temperature:
1. Thermophiles
2. Mesophiles
3. Psychophiles

THERMOPHILES
*Thermo = heat
*Philes = love
The microorganism that grow best at high temperature (heat loving microorganism).
These microorganism can live and grow at temperature > 50 degree celcius.
Can be found in hot spring or deep in the oceans by thermal vents bubbling up from the hot rocks just below the earth's crust.

MESOPHILES
Microbes that grow best at moderate temperature(20 to 40 degree celcius).
 Most of the microbes that grow on plants and animals and in the warm soil and water.

PSYCHOPHILES
Microorganisms that prefer cold temperature(-5 to -30 degree celcius). 
These microbes have enzymes that catalyze best when the conditions are cold, and have cell membranes that remain fluid at these lower temperature.

pH
refers to acidity and alkalinity of a solution.
most microorganism prefer a neutral or slightly alkaline growth medium (pH 7.0 to 7.4).

OSMOTIC PRESSURE
The pressure that is exerted on the cell membrane by solutions both inside and outside of the cell.
Osmotic pressure is related to the concentration of dissolved molecules and ions in a solution.

Chemical factors that influence the growth of microorganisms are:
1. Carbon
2. Nitrogen, sulfur and phosphorus
3. Water
4. Oxygen
5. Trace elements.

CARBON
is the basic structural component of organic compounds.
-Organic compounds = molecule that contain both carbon and hydrogen atoms.

NITROGEN, SULPHUR & PHOSPHORUS

• Synthesis of cellular materials.
• Protein synthesis need nitrogen and sulphur
• Synthesis of DNA and RNA.

WATER
is essential for life.
requirement for growth and reproduction.
-it contains essential nutrient for growth.
80% to 90% cell weight.
atmosphere humidity air level of 90% can encourage growth of microorganisms.

OXYGEN
essential for aerobes.
-because it produce most of the ATP (energy) for them.
also essential for organic growth factors.

TRACE ELEMENTS
Trace elements = other elements because they required in very small amounts.

helminths(cacing)

Helminths:

• Derived from Greek meaning worm.
• Helminths are higher, multicellular forms of parasite with specialized organs.(Baumann, 2007)
• Can be found throughout natural world.

Cestodes - Tapeworms

• Cestodes are members of Phylum Platyhelminthes.
• Commonly called tape worms.
• Cestodes are flat, segmented, intestinal parasites that completely lack digestive systems.
• Always reside in the gut of definitive host (human).
• Adult worms obtain nourishment from semi digested food of the host.
• Some tapeworms produce proglottids large enough to be obviously visible in stools.
• Length of tapeworms = 3 to 10 meter.

common terminologies

ANTISEPTIC: chemical agent that kills or inhibits microbial growth on the skin/tissue but is not harmful to human skin.
Antifungal agents:

• Agents that kill or inhibit the growth and reproduction of fungus.
• Example: Diflucan (Fluconazole).

ASEPSIS: free from pathogens or absent of the microorganism.

ANTITOXIN:

• Antibodies formed by the host to protect against toxins and neutralizing the toxin.
• Example: Antitetanus Toxoid (ATT)