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Chapter 6: Microbial Nutrition - Coggle Diagram
Chapter 6: Microbial Nutrition
:six::black_circle::one: Nutrients
Chemical substances acquired from the environment by cellular activities and used for growth.
used to form hundreds of chemical compounds inside a living cell.
95 % C, O, H, N, S, P, K, Ca, Mg, Fe
Requirement for
source of
carbon
for basic structures
source of
cellular energy
to drive metabolic reactions (ATP)
source of
high energy electrons/H, reducing power
(NADH/ NADPH)
Requirements
Macronutrients (macromolecules)
require in large amounts
C, O, H, N, S, P ,K, Ca, Mg, Fe
K- enzymatic activity (protein synthesis)
Ca- heat resistance (bacterial endospores)
Mg- co-factor for enzyme, stabilizer to ribosome & PM
Fe- ATP synthesis (electron transport)
Micronutrients (trace elements)
require in small amounts
Mn, Zn, Co, Mo, Ni, Cu
enzymes & co-factor as catalyst
maintenance protein structure
CHOPNS
CHOElectron
C-backbone of organic comp
HO- in organic compund
E- energy production, reduction of CO2
PNS
Organisms nutritional types
:red_circle: Energy source
Photoautotrophs
light
Chemotrophs
O I
:red_circle: Carbon source
Lithotrophs
I
Organotrophs
O
:red_circle: Electron source
Autotrophs
CO2
Heterotrophs
O
Energy+ Electron+ Carbon
eg: Chemoorganoheterotrophy
growth factors
Amino acid- for protein synthesis
Purines & Pyrimidines- nucleic acid synthesis
Vitamins- enzyme cofactors
:six::black_circle::two: Uptake
Simple diffusion
@ passive diffusion
:arrow_up: to :arrow_down: conc
small molecules across lipis bilayer
:red_cross: energy
eg: H2O, O2, CO2
Facilitated diffusion
:arrow_up: to :arrow_down: conc
:red_cross:energy
protein channels @ carrier protein
larger molecules
eg: glucose, amino acids, fatty acids, glycerols
Active transport
:arrow_down: to :arrow_up: conc
:check: energy
carrier proteins
Group translocation
:check: energy
chemically modifies into cell
@ system transport phosphoenolpyruvate- PTS
Endocytosis
Large substances into cell
vacuoles
in eukaryotic only
eg: phagocytosis of bacteria
phagocytosis
makan
engulf particles
phagosome
pinocytosis
minum
engulf liquid
pinosome
:six::black_circle::three: Culture media
physical nature
liquid
semisolid
solid
chemical composition
defined @ synthetic
known
specific requirements
prepared for research purpose
eg: minimal media used in bacterial genetics exp
complex
unknown
widely used
eg: nutrient broth, Luria-Bertani agar, potato dextrose agar
plant @ animal extracts- beef, yeast, soybean meal, casein, milk protein
digested proteins- peptone, tryptone
sulfated polysaccharide- agar used to solidify liquid media
functional type
supportive @ general purpose
support growth many microorganisms
Gram+ & Gram-
eg: tryptic soy agar, nutrient agar
enriched
supplemented
add blood, serum, vitamins, eggs
support growth of fastidious organisms
eg: blood agar, chocolate agar, Lowenstein-Jensen (LJ) medium
selective
allow some, inhibit others
eg: MacConkey agar & Eosin methylene blue (EMB) agar
both growth Gram-, inhibit Gram+
MacConkey- bile salts & crystal violet dye inhibit Gram+
EMB- eosin & methylene dye toxic to Gram+
differential
distinguish based on biological characteristics
eg: MacConkey agar, EMB agar- lactose fermenters VS non-lactose fermenters
eg: blood agar- hemolytic VS non-hemolytic bacteria
Lac+ (
E.coli
)- pink
Lac- (
Pseudomonas sp
)- colourless
pH indicator 6.8-8.0 changes color
Beta hemolysis- complete lysis
Alpha hemolysis- partial lysis
Gamma hemolysis- no hemolysis
example
Mannitol salt agar
selective- only
Staphylococcus sp.
differential
S.aureus
- turns yellow
S.epidermis
- not grow
CHROMagar
identify urinary trach pathogens
Blood agar
enriched
differential
EMB agar
selective
differential
MacConkey agar
selective
differential
:six::black_circle::four: Isolation of pure cultures
pure culture
population of single cell
single species
techniques
streak plate method
spread plate method
using spreader
on medium
pour plate method
mixed agar and cells
on & in medium
morphological observation
shape
circular
rhizoid
irregular
filamentous
spindle
margin
entire
undulate
lobate
curled
rhizoid
filamentous
size
punctiform
small
moderate
large
elevation
flat
raised
convex
pulvinate
umbonate
texture
smooth
rough
appearance
glistening @ shiny
dull
pigmentation
nonpigmented (cream, tan, white)
pigmented (purple, red, yellow)
optical property
opaque
translucent
transparent