Week 4: Microbial Growth in Vitro
Cards (122)
- Microorganisms that grow best at high temperatures. Found in Hot springs, compost pit and silage as well as in hydrothermal vents at the bottom of the ocean.
- Organisms that favor temperature above 100C.
- 113C
- Microbes that grow best at moderate temperature
- Include most of the species that grow on plants and animals and in warm soil and water.
- Grows best at normal body temperature, 37C.
- Prefer cold temperature.
- What is the optimum growth temperature of psychrophiles?
- Microorganisms that prefer warmer temperatures, but can tolerate or endure very cold temperature and preserved in the frozen state.
- Refers to hydrogen ion concentration of a solution and, thus the acidity or alkalinity of the solution.
- Prefer pH 2 to 5
- Prefer an alkaline environment pH greater than 8.5
- The bacterium that causes cholera. ONLY human pathogen that grows well above pH 8.
- Is the pressure that is exerted on a cell membrane by solutions both inside and outside the cell.
- Cells lose water and shrink when placed into a
- When the concentration of solutes in the environment outside of a cell is greater than the concentration of solutes inside the cell, the solution in which the cell is suspended is said to be
- Movement of a solvent through a permeable membrane from a solution having a lower concentration of solute to a solution having a higher concentration of solute.
- If the cell is a human cell, such as a red blood cell (erythrocyte), the loss of water causes the cell to shrink; this shrinkage is called ? and the cell is said to be ?
- If the cell is a bacterial cell, having a rigid cell wall, the cell does not shrink. Instead, the cell membrane and cytoplasm shrink away from the cell wall. This condition, known as
- When the concentration of solutes outside a cell is less than the concentration of solutes inside the cell, the solution in which the cell suspended is
- When the concentration of solutes outside a cell equals the concentration of solutes inside the cell, the solution is said to be
- Those microbes that actually prefer salty environments (such as the concentrated salt water found in the Great Salt Lake and solar salt evaporation ponds) are called
- are capable of surviving there (such as Staphylococcus aureus) are referred to as
- Thrive deep in the ocean and in oil wells, where the atmospheric pressure is very high.
- Refers to the proliferation or multiplication of bacteria.
- The time taken for one cell to become two cells by binary fission.
- Have generation time of about 20 minutes
- Pseudomonas and Clostridium spp. may divide every
- Mycobacterium tuberculosis may divide only every
- Have complex nutritional requirements
- Media that are used in microbiology laboratories to culture bacteria
- Is a complex polysaccharide that is obtained from a red marine alga, it is used as a solidifying agent, much like a gelatin is used as a solidifying agent in the kitchen.
- Is a broth or solid medium containing a rich supply of special nutrients that promotes the growth of fastidious organisms.
- Blood agar and Chocolate agar
- Is used to culture important, fastidious, bacterial pathogens, such as Neisseria gonorrhoeae and Haemophilus influenzae, which will not grow on blood agar.
- Has added inhibitors that discourage the growth of certain organisms without inhibiting growth of the organism being sought. For example, MacConkey agar inhibits growth of Gram-positive bacteria and thus is selective for Gram-negative bacteria.
- Differentiates between lactose-fermenting (LF) and nonlactose-fermenting (NLF) Gram-negative bacteria.
- a liquid medium involves adding a portion of the specimen to the medium.
- Inoculation of a solid or plated medium involves the use of a sterile inoculating loop to apply a portion of the specimen to the surface of the medium; a process commonly referred to as