Topic 7 Flashcards
What are the macromolecules (elements and cations) microbes require?
C, O, H, N, P, S and Mg2+, Ca2+, Fe2+, K+
What are the micronutrients required for microbes?
Co, Cu, Mn, and Zn
What are autotrophs?
organisms that fix CO2 into organic molecules
What are phototrophs?
organisms that obtain energy through light reactions
What are chemotrophs?
Organisms that obtain energy through redox reactions
What are lithotrophs?
chemotrophs that use inorganic molecules as a source of electrons
What are organotrophs?
chemotrophs that use organic molecules as a source of electrons
What are heterotrophs?
organisms that use organic carbon sources from autotrophs
What are diazotrophs?
use O2 sensitive nitrogenase enzyme to convert inorganic nitrogen into ammonium so other organisms can use it
What is a complex media and what microbes might it be used for?
nutrient rich medium but unknown chemical composition; heterotrophs
What is a minimal defined media and what microbes might it be used for?
contains only essential for growth nutrients; autotrophs
What is an enriched media and what microbes might it be used for?
a type of complex media in which specific growth factors are added; molicutes
What is a selective media?
favours the growth of one organisms over another
What is a differential media?
exploits biochemical differences between two microbes growing
What are oligotrophs?
grow optimally at low nutrient concentrations
What are the pros of broth and solid medium?
Broth - a closed culture that maximizes number of microbes
Solid - open system, can visualize microbes and count colonies
What is the generation time and how is it calculated?
the time it takes for a population to double; N0 x 2^n
What occurs during the stationary phase of cell growth?
cell numbers stop rising due to a lack of key nutrients, cells adapt by sporulating or becoming smaller
