Ch. 6 - Microbial Growth Flashcards

List 3 physical requirements for microbial growth

microbes that grow best between 0 - 15 degrees celcius

microbes that grow best between 20 - 30 degrees celcius, refrigerator temperature

microbes that grow best at high temperatures, 50 - 60 degrees celcius

microbes that grow best at moderate temperatures of 25 - 45 degrees celcius

optimum temperature for pathogenic bacteria

microbes with an optimal growth temperature above 80 degrees celcius

microbes that grow in deep ocean or polar areas

microbes that grow in hot springs

neutral pH

acidic level of pH

true or false. Bacteria produced in labs grow acids that interfere with bacterial growth.

peptones, amino acids and phosphate salts

true or false. Endospores are usually heat resistant

Percentage of water microorganisms are composed of

effect of high osmotic pressure

environment where the concentration of a solute is greater than the concentration of water in the cell

loss of cellular water causing the cell's cytoplasm to shrink

true or false. cell growth is inhibited by plasmolysis because the cytoplasm shrinks and pulls away from the cell wall

true or false. the addition of salts and increase in osmotic pressure can aid in the preservation of food

microbes that adapt to high salinity

microbes that require high salinity for growth

microbes that do not require high salinity, but are able to grow at salinity of 2%

complex polysaccharide from marine algae

used to solidify microbial growth medium

list 5 chemical requirements for microbial growth

structural backbone of living matter

microbes that derive carbon from carbon dioxide

microbes that derive carbon from organic material

elements required for protein synthesis

elements required for DNA and RNA synthesis

process of using gaseous nitrogen from the atmosphere

element required for synthesis of nucleic acid & phospholipids

essential for enzymatic functions

required by life forms for aerobic respiration

microbes that require oxygen to live

bacteria that can continue to grow in the absence of oxygen using fermentation

example of a facultative anaerobe

microbes unable to use oxygen for energy yielding reactions

example of an obligate anaerobe

list 2 toxic forms of oxygen

highly reactive oxygen at higher energy levels

requires superoxide dismutase to neurtralize atmospheric oxygen

can not use oxygen for growth and ferment carbohydrates to lactic acid

microbe used in pickles and cheese

microbes that require oxygen and grow in oxygen concentrations less than air. sensitive to superoxide radicals

organic compounds an organism is unable to synthesize

Three dimensional structure visible using a confocal microscope

complex polymer in a biofilm

cell to cell communication which allows bacteria to coordinate cellular activity

advantageous in facilitating transfer of genetic information

process where planktonic bacteria attach to a surface and form pillar like structures

essential in sewage treatment

percentage of human bacterial infections involving biofilms

nutrient material prepared for growth of microorganisms in a lab

microbes introduced into a culture medium

list 6 criteria necessary for a culture to grow in a culture medium

added to a medium when it is desired to grow a bacteria on a solid medium

hard to degrade and liquefies at 100 degrees Celcius

Media where the exact chemical composition of a microbe is known

organisms requiring many growth factors

example of a fastidious organism

used to determine the vitamin concentration in a substance

composed of nutrients including extracts fron yeasts, meats or plants

result of acid reduction in proteins. are digestable by bacteria

liquid form of complex media

media after agar is added

true or false. agar is a nutrient

uses sodium thioglycolate to combine with dissolved oxygen and deplete oxygen in culture mediu

list 2 methods used for anaerobic growth

Microbes that do not grow on artificial media. Require a living host.

used for aerobic bacteria requiring carbon dioxide levels less than or greater than those found in the atmosphere

true or false. high carbon dioxide levels can be obtained through the use of candle jars

an example of a microorganism requiring a living host

microbes that grow at high carbon dioxide concentrations

microbe cultured using chemical packets generating carbon dioxide

suppresses the growth of unwanted bacteria and encourages growth of desired microbes

used to isolate gram negative Salmonella typhi

isolates fungi growing at a pH of 5.6

distinguishes colonies of desired organisms from other organisms growing on the sane plate

used to identify bacterial species destroying red blood cells

example of a blood agar medium that show clear ring around colonies

usually a liquid medium used to detect bacteria in small numbers

media used for growth of obligate anaerobes

media designed to increase the number of microbes to a detectable level

most commonly used isolation method

Name the 2 methods for preserving bacterial cultures

true or false. Refrigeration can be used for long term storage of cultures

pure culture suspended in liquid and quickly frozen at =50 to -95 degrees celcius

bacterial preservation method where culture can be thawed years after culture has been preserved

suspended microbes are quickly frozen at temperatures fro -54 to -72 degrees celcius and undergoes sublimation

list 4 methods of bacterial division

most common method of bacterial division

methods by which filamentous bacteria divide

the time required for a cell to divide and population double

method of graphing bacterial populations

list the 4 phases of bacterial growth

phase of bacterial growth with little or no cell division, but intense metabolic activity

phase of bacterial growth where cells actively reproduce and generation time remains constant

phase of bacterial growth where logarithmic plot produces an ascending straight line

phase of bacterial growth where microbial deaths balance to number of new cells

phase of bacterial growth where the number of cell deaths exceeds new cells

list 4 methods of measuring microbial growth

method of measuring microbial growth where colonies on plates are counted and recorded as colony-forming units

method of measuring bacterial growth where bacteria is sieved out of a liquid suspension onto a thin membrane

method of measuring microbial growth where a sample is diluted out in a series of tubes of liquid medium

method of measuring microbial growth where a microscope is used to count cell in microscopic field

list 3 indirect methods of measuring microbial growth