Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
CH 6 Microbiology
Microbial Growth
| Term | Definition |
|---|---|
| Psychrophiles | cold-loving microbes Max growth temp- 20 degrees celsius |
| Mesophiles | moderate-temperature-loving microbes optimum growth temp- 25-40 degrees celsius Most spoilage and pathogenic microbes |
| Strict Psychrophiles | optimum growth 15 degrees celsius |
| Psychrotrophs | optimum temperature of 20- 30 degrees celsius most common in cases of low-temperature food spoilage |
| optimum growth temperature | temperature at which an organism grow best |
| minimum and maximum growth temperatures | provide the range of temperatures that an organism can survive in |
| Thermophiles | heat-loving microbes optimum growth temperature 50-60 degrees celsius minimum growth temperature 40 degrees celsius |
| hyperthermophiles | optimum growth temperature of 80 degrees celsius or higher some archaea |
| acidophiles | bacteria and other microbes that prefer acidic conditions |
| obligate halophiles | require high salt concentrations and lower water concentrations to function |
| facultative halophiles | prefer normal water concentrations max 98% min 85% |
| obligate aerobes | require oxygen to survive |
| facultative anaerobes | can survive without oxygen but grow more in the presence of oxygen |
| Microaerophiles | require low amounts of oxygen to survive higher concentrations are toxic |
| Aerotolerant anaerobes | survive equally well with or without oxygen |
| obligate anaerobes | require the absence of oxygen |
| biofilms | communities of microbes in thin layers on various surfaces |
| culture medium | nutrient material used for microbe growth |
| inoculum | microbes added to a culture medium to initiate growth |
| culture | group of microbes growing in/on a culture medium |
| sterile | culture medium (or other substance) without any microbes present |
| agar | polysaccharide derived from algae used to generate solid culture media |
| chemically defined medium | culture medium where the exact chemical composition is known |
| minimal medium | a type of chemically defined medium with the minimal amount of nutrients for microbe survival |
| selective medium | culture medium designed to optimize growth for specific organisms |
| differential medium | culture medium designed to allow easy identification of specific microbial cultures |
| complex medium | culture medium without an exact chemical composition |
| lag phase | occurs shortly after the bacterial inoculum is added to the culture medium |
| exponential growth phase | occurs when the bacteria start growing rapidly |
| stationary phase | occurs when environmental conditions slow down bacterial growth |
| death phase | occurs when cell deaths outnumber new cells being formed |
| generation time (of a culture) | time required for the live cell number in the culture to double |
| plate counts | number of colonies formed on a plate |
| serial dilutions (or repeated dilutions of a culture) | often necessary to reduce the number of microbes to a measurable number |
| direct microscopic count | quantitative test and used to enumerate the number of bacterial clumps or somatic cells present in milk |
| most probable number method | statistical process of estimating microbial population |
| turbidity | cloudiness of the culture medium |
| metabolic activity | measurement of nutrient consumption or waste product formation |
| dry weight | removal and drying of microbes and measurement of mass |
Created by:
kbarcenas9
Popular Biology sets