CP 6, Bacterial Growth and Nutrition

What is normal salt concentration?

1%.

What is the normal salt concentration for a Halophile?

3.5% is optimum for their growth.

What is a Candle Jar?

A candle is lit before the jar is closed. The burning candle uses the oxygen in the jar and adds carbon dioxide to it. When the carbon dioxide extinguishes the flame, conditions are optimum for the growth of MO that require small amts of C02.

Binary Fission

A cell duplicates it components and divides into two cells. The daughter cells become independent when a septum grows between them and separates.

Chemoautotrophs

A type of organism that is unable to carry out photosynthesis but can oxidize inorganic compounds for a carbon source and to obtain energy.

Chemoheterotroph

A type of organism that must consume organic compounds for their carbon source and to obtain energy.

What vitamins have no use?

A, C, D, and E.

Acidophiles

Acid-loving organisms. Grow best at a pH of 0.1 to 5.4. i.e., Lactobacillus.

What is a solid media?

Agar. A complex polysaccharide extracted from certain marine algae.

Alkaliphiles

Alkali-looving (base loving) organisms. Exist from pH 7.0 to 11.5. i.e., Vibrio cholerae.

Differential Media

Allows for a fast answer causes observable changes (colour by pH) in the medium when a particular reaction occurs.

What are the forms of Nitrogen used?

Amino acids to Proteins, Nucleotides to Nucleic Acids, Vitamins.

Vitamins

An organic substance that an organism requires in small amounts and that is typically used as a coenzyme.

Hyperthermophile

An organism that thrives in extremely hot environments— from 60 degrees C upwards. An optimal temperature for the existence is above 80°C.

Why is solid media better then liquid media?

Because you can get single colonies.

What is Carbons purpose?

Biological structure that is also an energy source.

What is an example of liquid media?

Broth.

What is the Gas Pak?

C02 incubator. Sealed jars containing chemical substances that remove oxygen from the air and generate C02.

Obligate Thermophiles

Can only grow at temperatures above 37*C.

What are the different ways Anaerobes are grown?

Candle jar, gas pak.

Stationary Phase

Cell division decreases to the point that new cells are produced at the same rate as old cells die, the number of live cells stays constant.

Psychophiles

Cold-loving organisms. Grow best at tmperatures of 15* to 20* C. Some can live at 0*C. Live mostly in cold water and soil. None can live in the human body, but some are known to cause spoilage of refridgerated foods and subsequent disease in humans, sometimes fatal.

Culture Medium

Collection of required nutrient for a given microorganism.

What are examples of Trace Elements?

Copper, Iron, Zinc, Cobalt, Sodium, Chloride, Potassium, Magnesium, Magnanese, Calcium.

What are the sources for Sulfur?

Cysteine and methinine.

Neutrophiles

Exist from pH 5.4 to 8.0.

What are some vitamins required by some MO?

Folic Acid, vitamin B12, and vitamin K.

What type of organisms use Photosynthesis?

Green and purple bacteria, cyanobacteria, algae, and higher plants.

Facultative Thermophiles

Grow both above and below 37*C.

Logarithmic Growth

Growth that is exponential.

Thermophiles

Heat-loving organisms, grow best at temperatures between 50* to 60*C. Found in compost heaps, and few tolerate temperatures as high as 110*C in boiing hot springs.

What are toxic oxygen compounds?

Hydrogen peroixde (h202), and super oxide (02).

Why are some Trace Elements required?

In small amounts in order to grow.

Autotrophs

Inorganic C02 is the carbon source. Self Feeders.

Chemically Defined Culture Media

Like a recipe, contains specific list of nutrients and their amounts. Known exact composition, number of nutrients and their amounts.

Thermoduric

Live as mesophiles but can withstand short periods of exposure to high temperatures.

What is Sulfur and Phosphorus's purpose?

Microorganisms need a supply of certain minerals, these are important to cell components.

Mesophiles

Most bacteria. Grow best at temperatures between 25* and 40* C. Human pathogens are included, most grow best near human body temperature (37*C).

What organisms are Photoheterotrophic?

Nonsulfer, purple or green bacteria.

Complex Culture Media

Nutrients are from biological sources (rich source of nutrients) Dont know exact composition.

What are Trace Elements?

Often serve as cofactors in enzymatic reactions.

Heterotrophs

Organic Compounds are the carbon source. Other feeders.

Photoautotrophs

Organisms that carry out photosynthesis. Light is the carbon source.

Lag Phase

Organisms that do not increase significantly in number, but they are metabolically active -grown in size, synthesizing enzymes, and incorperating various molecules from the medium.

What metabolic reactions produce toxic, reactive 02 biproducts?

Oxidizing agents.

What are the sources for Phosphorus?

Phospholipids and nucleic acids.

What are the main types of energy capturing metabolism?

Photoautotophs, chemoautotrophs, Photoheterotrophs, and chemoheterotrophs.

What are the criteria for culture media?

Proper nutrients, proper oxygen, proper moisture, proper pH, sterile, proper salts, proper temperature.

Selective Media

Provides a fast answer and immediate identification. Encourages the growth of some organisms, but suppresses the growth of others.

Exponential

Rapid increase.

Extreme Halophiles

Require a salt concentration of 20% to 30%. Found in the Dead Sea, or brine vats.

Microaerophile

Require a small amount of 02 for normal growth but are inhibited by 02 at normal atmospheric tension.

Halophiles

Salt loving organisms that require moderate to large quanitites of salt (sodium chloride).

Photoheterotroph

Small group of bacteria that can use light as a energy source but requre organic substances such as alcohols, fatty acids, or carbohydrates as carbon sources.

What is more beneficial solid media or liquid media?

Solid media.

What does Organic Growth Factors mean?

Some MO can not synthesize all compounds required for growth. These compounds must be supplied in media or by enviroment. These compounds can include amino acids, vitamins, nucleotides etc.

Photosynthesis

The capture of energy from light and the use of this energy to manufacture carbohydrates from carbon dioxide.

Maximum Growth Temperature

The highest tempearture at which cells can divide.

Minimum Growth Temperature

The lowest temperature at which cells can divide.

Decline (Death) Phase

The number of live cells decreases at a logarithmic rate. The condition in the medium is less and less supportive of cell division, many cells lose their ability to diviide and thus the cells die.

Obligate

The organism must have the specified environmental conditions.

Facultative

The organisms is able to adjust to and tolerate the environmental condition, but it can also live in other conditions.

Optimum pH

The pH at which a MO grows best. Usually pH 7.

Optimum Growth Temperature

The temperature at which cells divide most rapidly - that is have the shortest generation time.

What is Nitrogens purpose?

To synthesize enzymes, other proteins and nucleic acids.

What can oxygen be?

Toxic.

Enrichment Media

Try to increase the number of desired MO cells. Work in similar manner to selective media. Requires multiple steps, takes time to get answer. Does not inhibit others.

Facultative Anaerobe

Will grow either aerobically or in the absence, but prefer 02.

Obligate Anaerobe

Will grow only in absence of 02, and is harmed by 02.

Obligate Aerobe

Will grow only in the presence of 02.

Why is H20 required?

Without it, organisms cannot survive or grow.

Obligate Psychrophiles

i.e., Bacillus globisporus. Cannot grow above 20*C.

Facultative Psychrophiles

i.e., Xanthomonas pharmicola. Grows best below 20*C, but can also grow above that temperature.