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• What nutrients do microbes need for growth (what chemical elements do we need in the medium)? Macroelements (C, H, O, N, P, S), cations (K+, Ca2+, Mg2+), Organic compunds
• Which organic compounds do we need in the medium and how do we know that? Trace DNA --> see what organism can produce, aminoacids, lipids, vitamins etc
• What different types of microorganisms are their, when speaking about O2? obligate aerob, microaerophiles, facultative-, aerotolorant-, strict anaerob
• What does it mean when a specie is obligate aerob? Needs oxygen to survive (top of test tube)
• What does it mean when a specie is strict anaerob? Oxygen is toxic for the organism (bottom of test tube)
• What does it mean when a specie is microaerophiles? Need a little bit of oxygen (top/center of testtube)
• What does it mean when a specie is facultative anaerob? Prefers oxigen (top half of test tube)
• What does it mean when a specie is aerotolorant anaerob? It doesn't need oxygen, yet it is not toxic
• What different types of microorganisms are their, when speaking about pH-levels? Acidophiles, Neutrophiles, Alkaliphiles
• What is the difference between Acidophiles, Neutrophiles and Alkaliphiles? Acidophile < 5.5, neutrophiles - neutrals and alkaliphile > 8
• What different types of microorganisms are their, when speaking about temperature? Psychrophiles, Psychrotrophs, Mesophiles, Thermophiles, Hyperthermophiles
• What is water activity a(w)? Partial preassure a(w) = P/P(0) where P(0) is preassure for pure water
• How does nutrition affect the growth of microorganisms? Growth rate μ increases [substrate] up to a saturation limit μ(max)
• What is generation time and how is it calculated? The time to double population, t = ln2 / μ
• How is the growth calculated and what part of the S-curve does it match? X = X0 * e^μt, match BEFORE stational phase
• What is the Monod Equation and what does it describe? if put in growth equation --> S-curve, μ = μ(max) * S / (Ks + S)
• What is Ks and how is it found on the S-curve? The saturation of nutrition when μ = 1/2 μ(max)
• Which methods can be used to determine the growth rate in the lab? Optical density, cell dry weight, cell number methods
• What is optical density, OD? Spectrophotometer measures light scattering --> population growth
• What is Cell Dry Weight (CDW)? Cells are filtered, washed and dried to then be weighed
• What is Colony Forming Units (CFU)? Spread on agar plate then colonies counted to meassure viable cells
• What is Flow Cytometry? Cells passes laser beam that cound the amount of cells
• What does phage mean? It is a type of fiber for bacteria
• How can the cells adapt to the pH-level and how does it affect the cell? By transporting protons out of the cell, uses ATP --> growth stops
• What does it mean that the organism is O2-tolerant? That it can convert toxic forms of oxygen, radicals, into O2 and H2O
• What does Xerophilic mean? Dryloving
• What does Halophilic mean? Saltloving
• What is the difference between hypotonic and hypertonic solutions? Hypo = [C] higher inside, Hyper = [C] higher outside
• How can the cell prevent water from going in when hypotonic solution? Create proteins from lose aminoacids --> reduce volume --> less H2O in
• How can the cell prevent water from going out when hypertonic solution? Pumps K+ into the cell --> ion - dipol --> less water going out
• How does temperature affect the membrane? High T: loser + coagulated proteins, Low T: solid + metabolism cease
• What is a biofilm and why does some bacteria create it? exopolysacarides as protective layer from outer toxins (ex. antibiotics)
• What is binary fussion? A way for cells to multiply (copy genome --> split into 2)
• What is budding? Most common for yeast to multiply (pops of young cell from mother cell)
• What are the different phases in the growth curve called? Lag phase, Exponential phase, Stationary phase, Death phase

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