L6 Bacterial Persistence at the Aerobic-Anaerobic interface Flashcards
define aerobic bacteria
prefer oxic environments
21% O2, atmospheric
define microaerobic
hypooxic environments trace O2 (2-10%)
define anaerobic
anoxic environments
strictly 0%
facultative (can live in both)
what is eutrophication
dead zones (environmental hypoxia)
types of bacteria environments and oxygen status
host associated: internal or bacteria dense are anaerobic
soils and oceans: decreasing O2 with increasing depth
what feature do bacteria have that enables to be live in a diverse range of environments
can have multiple electron donors and accepters
fermentation is sustainable for long periods of time
FLEXIABLE
why can bacteria live on so many surfaces
diverse range of digestive enzymes for breaking down polymers
how does bacteria break down polymers from the environment
enzymes produced inside the cell are transported to the surface where they break down polymers intro monomers and oligomers for the conserved intracellular metabolic pathways
what is bacterial persistence
when bacteria are growing slowly or not at all
not dying, still metabolically active
not going through lag or log phase
is bacterial true dormancy
no, endospores would be an example of true dormancy
what is an r-type strategy
fast growing
use nutrients they don’t need
bust and boom
dynamic persistence of small subpopulation
what is a k-type strategist
uses food efficiently
slow growing
bulk population persists
less drastic metabolic changes under stress
example of r-type strategists
E. Coli
B. subtilis
example of K-type strategist
M. tuberculosis
define antibiotic resistance
Heritable
genetic changes that allow bacteria to grow
