Microbial GrowthSlide 2TemperatureSlide 4Slide 5Slide 6pHSlide 8Water ActivitySlide 10Slide 11CarbonMetabolic DiversitySlide 14Oxygen RequirementsSlide 16Slide 17Slide 18Slide 19Growth in liquid mediaSlide 21NitrogenSulfurPhosphorusMicroelementsGrowth FactorsCultivation Of MicroorganismsTypes Of Culture MediaSlide 29MacConkey’s AgarSlide 31Slide 32Microbial GrowthSlide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Microbial Growth Microbial Growth Factors that influence growth:Factors that influence growth:Physical/EnvironmentalPhysical/EnvironmentalChemical/NutritionalChemical/NutritionalMicrobial adaptations are remarkable Microbial adaptations are remarkable Extremeophiles Extremeophiles May adapt to a point of no return May adapt to a point of no returnTemperatureTemperature Microbes within different ranges (Microbes within different ranges (--202000C – 120C – 12000C)C)Min and max typically ~ 30°C apartMin and max typically ~ 30°C apartOptimum temp closer to max than min Optimum temp closer to max than minPsychrophiles: Psychrophiles: Optimum temperature ~15°COptimum temperature ~15°CPsychrotrophs (moderate psychrophiles)Psychrotrophs (moderate psychrophiles)Optimum temperature ~25°COptimum temperature ~25°CMesophiles:Mesophiles:Optimum temperature ~37°C Optimum temperature ~37°CThermophiles:Thermophiles:Optimum temperature ~60°COptimum temperature ~60°CHyperthermophiles:Hyperthermophiles:Optimum temperature above 70°COptimum temperature above 70°CUsually ArchaeaUsually ArchaeapH pH Most microbes are neutrophiles (6.5 – 7.5)Most microbes are neutrophiles (6.5 – 7.5)Optimum pH of most bacteria is 7 Optimum pH of most bacteria is 7 Some bacteria are considered acid tolerantSome bacteria are considered acid tolerantHelicobacter pylori Helicobacter pylori Typically fungi grow over a wider pH rangeTypically fungi grow over a wider pH rangeUsually responsible for spoilage of acidic foodsUsually responsible for spoilage of acidic foodsAcidophiles optimum is lower (below 5.5)Acidophiles optimum is lower (below 5.5)Sulfolobus - Sulfolobus - Archaea from acidic hot springs Archaea from acidic hot springs Lactobacillus – Lactobacillus – BacteriaBacteria produces lactic acidproduces lactic acidThiobacillusThiobacillus - Bacteria produces sulfuric acid - Bacteria produces sulfuric acid Alkalophiles have optimum above 8.0Alkalophiles have optimum above 8.0Bacillus alcalophilusBacillus alcalophilus ~ 10.5 ~ 10.5Vibrio choleraeVibrio cholerae prefers pH of 9.0 outside host prefers pH of 9.0 outside hostWater ActivityWater ActivityOsmotic Pressure Osmotic Pressure AdaptationsAdaptations inclusion bodies, compatible solutes, stretch receptorsinclusion bodies, compatible solutes, stretch receptorsFacultative halophilesFacultative halophilesOsmotolerant/HalotolerantOsmotolerant/HalotolerantStaphylococcus aureusStaphylococcus aureusFungi tend to be more tolerant than other microbesFungi tend to be more tolerant than other microbesObligate halophilesObligate halophilesMost marine microbesMost marine microbesExtreme halophilesExtreme halophilesSalt flats of Utah and Dead SeaSalt flats of Utah and Dead SeaAll organisms need:All organisms need:MacroelementsMacroelementsCHNOPSCHNOPSMicroelementsMicroelementsK, Ca, Cl, Na K, Ca, Cl, Na Trace elements Trace elements Growth factorsGrowth factorsCarbonCarbonOne of the most important growth requirementsOne of the most important growth requirements½ the dry weight of a bacteria cell is carbon½ the dry weight of a bacteria cell is carbonCarbon skeleton base of organic compoundsCarbon skeleton base of organic compoundsHydrocarbonsHydrocarbonsMetabolic DiversityMetabolic Diversity Organisms grouped by energy, carbon and electron sourceOrganisms grouped by energy, carbon and electron sourceEnergy Source Energy Source Phototroph or ChemotrophPhototroph or ChemotrophCarbon SourceCarbon SourceAutotroph or HeterotrophAutotroph or HeterotrophElectron SourceElectron SourceLithotroph or OrganotrophLithotroph or OrganotrophPhotolithoautotrophPhotolithoautotrophCOCO22, Light and inorganic e- donor, Light and inorganic e- donorChemoorganoheterotrophChemoorganoheterotrophOrganic carbon, organic chemicals and organic e- donorOrganic carbon, organic chemicals and organic e- donorChemolithoautotrophChemolithoautotrophCOCO22, inorganic chemicals and inorganic e- donor, inorganic chemicals and inorganic e- donorPhotoorganoheterotrophPhotoorganoheterotrophOrganic carbon, light and organic e- donorOrganic carbon, light and organic e- donorChemolithoheterotrophChemolithoheterotrophOrganic carbon, inorganic chemicals and inorganic e- donorOrganic carbon, inorganic chemicals and inorganic e- donorOxygen RequirementsOxygen RequirementsOxygen has many toxic forms Oxygen has many toxic forms Organisms require enzyme systems to protect them Organisms require enzyme systems to protect them Superoxide (OSuperoxide (O22--) radical) radicalNeutralized by superoxide dismutase (SOD)Neutralized by superoxide dismutase (SOD)2 O2 O22- - + 2 H+ 2 H+ + → → HH22OO22 + O + O22Peroxide Peroxide Detoxified by catalase or peroxidaseDetoxified by catalase or peroxidaseCatalase: HCatalase: H22OO22 → H → H22O + OO + O22Peroxidase: HPeroxidase: H22OO22 + 2 H + 2 H+ + → 2 H→ 2 H22OOObligate (Strict) AerobesObligate (Strict) Aerobesonly aerobic metabolismonly aerobic metabolismHave SOD and catalase or peroxidaseHave SOD and catalase or peroxidase Obligate (Strict) AnaerobesObligate (Strict) AnaerobesDestroyed by oxygenDestroyed by oxygenDo not have SOD, catalase or peroxidase Do not have SOD, catalase or peroxidase only anaerobic metabolismonly anaerobic metabolismFacultative AnaerobesFacultative AnaerobesHave SOD and catalase or peroxidaseHave SOD and catalase or peroxidaseGrow with or without oxygenGrow with or without oxygen aerobic or anaerobic metabolism aerobic or anaerobic metabolism Grow faster in the presence of OGrow faster in the presence of O22Aerotolerant AnaerobesAerotolerant AnaerobesHave SODHave SODGrow with or without oxygenGrow with or without