growth and nutritionfaculty.collin.edu/mweis/microbiology/lecture/adobe...
TRANSCRIPT
Bacterial Requirements
Growth and Nutrition
Bacterial Reproduction
ReproductionBinary FissionBuddingFragmenting
FunctionIncrease number of cellsGenetic recombination possible
End result : Growth
Generation Time
DefineTimeReasonRequirements
PhysicalChemical
ResultGenetic recombinationMutations
Growth Curve Graph
Growth Curve Labeled Phases
Lag phaseAdaptiveStart metabolism1-3 days
Log phaseGeneration time doublesMost metabolically active
Stationary phaseGrowth = death
Death phaseRequirements decreasePossible spore formation
Growth Curve Changes due to AB
Measurement of Microbial Growth
CFUSerial DilutionsPour PlateSpread PlateDirect
Number counted / fovIndirect
TurbidityMetabolic activity
Nutritional Requirements
Macro and Trace Elements
Nutritional Element Use
CarbonOxygenNitrogenHydrogenPhosporusSulfur
Main componentCell water, aerobic respirationAA, NA, coenzymesH20Nucleotides, PL, LPSSeveral AA; coenzyme
Cycles
Metal Ions and Trace Minerals
PotassiumMagnesiumCalciumIronCoboltZincCopperManganese
Cofactors in enzymatic reactions in the cell
Growth Factors: Vitaminsinvolved in many
Metabolic Reactionsredoxdeaminationdecarboxylationtransaminationsynthesis
Folic AcidBiotinNiacinPantothenic acidRiboflavin [B2]Thiamine [B1]Pyridoxine [B6]B12K
Oxygen Requirements
Obligate AerobesMicroaerophilesAerotolerant aerobesObligate AnaerobesFacultative AnaerobesCapnophiles
Oxygen Requirement Classification
Aerobic / Anaerobic Lab Tests
aerobe FA aerotolerant anaerobe
Oxygen Forms
NormalToxic
Singlet: 1O2 with electrons in higher energy stateSuperoxide radical: O2-Peroxide Anion: O2=Hydroxide radical: OH-from incomplete reduction of hydrogen peroxide [H2O2]
Enzyme Presence to Detoxify O2 -Superoxide Catalase Peroxidase
Abligate Aerobes and FA + + -Aerotolerant Anaerobes + - +Obligate anaerobes - - -
Catalase Test
Bacterial Examples of O2 Groups
Obligate AerobesPseudomonas
MicroaerophilesH. pylori
Aerotolerant aerobesStreptococcusLactobacillus
Obligate AnaerobesClostridium
Facultative AnaerobesE. coliStapylococcus
CapnophilicCampylobacter
E coli
Staph
Physical Requirements: pH
pH Groups
AcidophileBacillus acidocaldariusLactobacillus acidophilus
NeutrophileE. coliStaphylococcus aureus
AkaliphileStreptococcus pneumoniaeNitrobacter sp.
Physical Requirements: Temperature
PsychrophileUnsaturated FA in cell membrane
PsychrotrophRefrigerationRoom temperature
MesophileWarm Blooded Animals
ThermophileSaturated FA in cell membrane
Psychrotrophs and Mesophiles
Bacterial Examples: Temperaturepsychrophile psychrotroph
mesophile thermophile
mold
Archaea
Vibrio
E coli
Physical Requirements: Salt
Extreme Halophile : 30 % NaClObligate Halophile : 15% NaClFacultative Halophile : 2% NaClHalotolerant : NaCl not needed, can grow in low salt
Extreme Halophiles
Great Salt Lake
Osmosis and Water Activity
Activity of water [Aw] = 1.0 for pure water
Aw for human blood = 0.99
Range required 0.7-1.0 AwE.coli requires Aw of 0.91Stapylococcus requires Aw of 0.85
Nutritional Groups
PhotoautotrophsChemoautotrophsPhotoheterotrophsChemoheterotrophs
Many bacteriaMost all Eukarya
How Acquire ElectronsOrganotrophsLithotrophs
Symbiotic Relationships
Close ecological relationship between individuals of two or more different species
MutualismCommensalismSynergismParasitismCompetitionNeutralismBiofilms
Mutualism: Both Benefit
Human Eye-lash mite
Bacterial Symbiosis
Biofilms
Parasitism
Agar
Culturing Organisms
InoculumMediumPure CultureSterile
Cultivation Media
Chemically DefinedComplex Undefined
General UseEnrichedSelectiveDifferentialAnaerobic
Cultural Characteristics
Solid Media [Petri]ColorSizeShape ElevationMargin
Broth MediaSlantGelatin Liquefaction
Colony Characteristics on Agar Plate
Complex General Media:Nutrient (TSA) Agar
Enriched Media
Selective and Differential Media
C-CNA MAC
MSA EMB
Special Media
SABMH-T
SS Snyder Deep
Anaerobic Culture Methods
Isolation Techniques
Biochemical Reactions
Questions?