Bacterial growth Flashcards
Binary fision?
Asexual reproduction
Exponential growth
2^0 –> 2^1 –>2^2
Budding?
Unequal growth
One daughter cell dissimilar to the mother cell
Turbidity?
The cellmass and can be measured by the OD as light scatteres by cellmass.
Spectrophotometer?
Measures OD by the unscattered light from the cellmass. A wavelength is sett by the apparatus, ex OD600.
Generation time?
1 cell –> 2 cells and the time between the events.
Growth curve?
Lag
Exponential
Static
Death - Cryptic growth
Culture media?
Defined - pre. amounts of IN/O organic chemicals and dH2O
Complex - Digestive products and dH2O
Chemostat?
Medium added @ constant rate at the same time as spent is removed = Steady state where cell density and substrate [] do not change over time.
Factors affecting growth?
T
P
O
H
Temperature?
Rate of enzymatic activity in reactions
Cardinal temp - min -> opt -> max
Types of T bacteria?
Psychropiles - low temp Mesophiles - mid temp Thermopiles - >45 Hyperthermopiles - >80 Extremopiles - High or Low temp
Adaptations to T?
Cold - more alpha helices and less beta sheets and more polar
Cold shock proteins and cryoproteins
Hot -more beta sheets and more non-polar
pH?
How the extracellular enviroments pH can change and are usually in a range of 5-9.
Types of pH bacteria?
Neutropiles - 5.5-7.9
Acido piles - < 5.5
Alakalipiles - > 8
H2O?
Solutes binds to H2O and makes it less available
aw = 0–>1 and opt. @ 0.98
Types of NaCl basteria?
Halopiles - Req is absolute and can not be replaced by other solutes. 1-4% or 3-12%.
Halotolerant - Tol. some levels of dissolved solute
Extreme halopiles - 15-30% NaCl for growth
Osmopiles - Env. high in sugar
Xeropiles - Dry environment
Hyperosmotic shock?
Cells lyse due to efflux of H2O by a sudden change in the extracellular [] of solute.
Oxygen?
Shaking = aeration
Anoxic conditions - reducing agent
O2 –> H2O
Groups of Aerobes?
Obligate - req. O2
Faculative - not req.
Micrpoaerophilic - req O2 in small amounts
Groups of Anaerobes?
Obligate - Inhibited or die by oxygen
Aerotolerant - tolerant and can grow
Oxygen reduction?
O2- H2O2 OH* –> H2O
[R] Aerotolerant?
Proteinfree Mn - complex
O2-
[R] Anaerobes?
Superoxide reductase
O2- –> H2O2
No production of O2
[R] Aerobes?
Catalase
H2O2 –> H2O + O2
Dismutase
O2- + O2- –>H2O2 + H+ + O2
Thioglutamate browth?
To separate the bacteria in a glass tube
Redox –> Resazonin - Pink or colorless
Top - Obligate
Near top - Microaeropiles
Throughout - Faculative
Bottom - Anaerobes
