3/13/2016 Halotolerant Halophile Extreme Example: le 8t2gococeus io fischer salinarum -3% osmophile 15-30% extreme halophile mos bacte ia osmotolecant halotolerant, Nonhalophile 1.00 0.90 0.80 0.70 Example: Water Activity Aw NaCI (% Characteristics of the Organism Characteristics of the Organism Compatible solutes are small molecules that act as osmolytes and help organisms survive Glycine betaine and L-proline are the extreme osmotic stress main osmoprotectants for 5.aureus OH do not interfere with biochemical reactions -accumulate to very high levels in response to low water activity adjust water activity inside the cell lower the intracellular water synthesized or obtained from the growth activity to match that of the L-Prolin medium environment Osmoprotectants for growth at low water Transport into the cell requires activity energy Compatible solutes accumulate in the cell and Toxin may not be produced under enhance growth under osmotic pressure extreme conditions Glycine Betaine 6 3/13/2016 6 1-3% 15-30% Characteristics of the Organism • Compatible solutes are small molecules that act as osmolytes and help organisms survive extreme osmotic stress - do not interfere with biochemical reactions - adjust water activity inside the cell - synthesized or obtained from the growth medium • Osmoprotectants for growth at low water activity • Compatible solutes accumulate in the cell and enhance growth under osmotic pressure Characteristics of the Organism • Glycine betaine and L-proline are the main osmoprotectants for S. aureus - accumulate to very high levels in response to low water activity - lower the intracellular water activity to match that of the environment • Transport into the cell requires energy • Toxin may not be produced under extreme conditions