Microbial nutrition, growth requirements and bacterial metabolism Flashcards
-requires oxygen and grows well in room air
-15-21% oxygen, 1% CO2
aerobe
eg:
pseudomonas
bordetella
brucella
mycobacteria
PBBM
obligate aerobic
-does not require presence of oxygen
-dies in presence of oxygen
obligate anaerobic
eg:
clostridium
bacteroides
(CBac)
obligate anaerobic
-most clinically significant organism
-grows in either presence or absence of oxygen
-does not require oxygen but grows well with oxygen
facultative anaerobe
eg: enterobacteria
facultative anaerobe
obligate aerobes and facultative anaerobes contain protective enzymes (2) against toxic effect of oxygen
superoxidase dismutase
catalase
-can survive in presence of oxygen but will not perform metabolic process unless placed in anerobic environment
aerotolerant anaerobe
eg:
propionibacterium
lactobaciullus
(ProLac)
aerotolerant anaerobe
organism that requires 2-10% oxygen for growth
microaerophile
eg:
campylobacter
treponema pallidum
(CT)
microaerophile
requires 5-10% CO2
capnophiles
eg.
haemophilus influenzae
neisseria gonorrheae
streptococcus pneumoniae
(HaNeS)
capnophiles
CO2 % needed by aerobic bacteria
0.03%
according to carbon source:
use CO2 as sole source of carbon
autotrophs
according to carbon source:
use reduced, preformed organic molecules from other bacteria
heterotrophs
according to energy source:
organisms that use light
phototrophs
according to energy source:
organisms that use the energy produced by the oxidation of organic or inorganic compounds
chemotrophs
according to electron source:
-they reduce inorganic molecules
-same as autotrophs
litotrophs
according to electron source:
-require organic substances for growth and multiplication
-ALL BACTERIA THAT INHABIT HUMAN BODY
-same as heterotrophs
organotrophs
obtain energy either by photosyntetically or oxidatively
autotrophs
litotrophs
obtain energy by oxidation or fermenting organic substances such as glucose
heterotrophs
organotrophs
requires additional substances such as vitamins, purines, pyrimidines and hemoglobin for growth and survival
fastidious bacteria
require dead organic substances
saprophytes
requires organic substance from living tissues
parasites
optimum temperature for most bacteria
35-37c
according to temperature:
grows well at 0c to a maximum of 20c
psychrophile/cryophile
eg:
listeria monocytogenes
yersinia enterocolitica
psychrophile/cryophile
according to temperature:
grows between 20-45c
commonly encountered pathogenic bacteria in lab
mesophile
according to temperature:
grows beterrn 50-125c
thermophiles/hyperthemophile
according to temperature:
prokaryotes that are able to live at unusual conditions
eg: bacillus infernus
extremophiles
term:
the lowest minimum time required to kill organism in a constant temperature
thermal death time
term:
the lowest temperature required to kill organism at a constant time
thermal death point
measure of the hydrogen ion concentration of an organism’s environment
pH requirement
pH requirement:
pH 0-5.5
acidophile
pH requirement:
pH 5.5-8.0
neutrophile
pH requirement:
pH 8.5-11.5
alkalophile
pH requirement:
most clinically significant bacteria
neutrophile
optimum pH for most pathogenic bacteria is between -
6.5-7.5
requirement important for bacterial growth
moisture
requires increased concentration of sodium chloride
halophiles
pressure requirement:
organism that grow rapidly in presence of high pressure
barophilic
substances required by fastidious bacteria for their growth and multiplication
growth factors:
amino acids
vitamins
purines
pyrimidines
