Growth

Growth phases – lag,

exponential phase(log) – growth at maximal rate un/balanced growth – depends on nutrient levels and environmental factors

stationary – can occur because of lack of nutrients, sometimes o2 is only available for those on the surface, because it's not very soluble. Or waste accumulation, such as lactic acid [high pH] from streptococci(anaerobic)

starvation – protoplast shrinkage, nucleoid condensation, and starvation proteins make the bacteria more virulent. Stronger cell wall, chaperones prevent denaturation, Dps [dna-binding protein from starved cells, protect the dna]

death phase

coenocytic – multinucleate organism (such as fungi)

batch cultures – closed system (usually liquid) in which waste products can accumulate

Petroff-Hausser Counting machine

extremophiles (bacillus infernus) live in extreme environments

inclusion bodies? 49-52

Hypotonic environment can cause the cell the lyse, or the reverse is plasmolysis

Compatible solutes are compatible with metabolism, and used to modify the osmotic concentration to keep the cell turgid

water activity is tested by sealing a sample and waiting for equilibrium. Then the air humidity is compared to what pure water, which is humidity(air saturation) calculated over humidity of pure water (100%). This result describes the relationship between the solutions vapor pressure divided by pure waters vapor pressured, and gives us osmotic pressure/water activity.

Halophiles require high sodium environment because they have adapted to hypertonic environments by storing lots of K[potassium], which is now required for them to live.