Chapter 6 Microbial growth and metabolism Microbial nutrition Microbial growth Metabolism
Chapter 6 Microbial Growth and Metabolism • Microbial Nutrition • Microbial Growth • Metabolism
6-1. Microbial nutrition Outline Nutrient requirements Nutritional types of microorganisms Uptake of nutrients by the cell · Culture mediun Isolation of pure cultures
6 – 1. Microbial Nutrition • Nutrient requirements • Nutritional types of microorganisms • Uptake of Nutrients by the Cell • Culture Medium • Isolation of Pure Cultures Outline:
Concepts: Microorganisms require about ten elements in large quantities, because they are used to construct carbohydrates, lipids, proteins, and nucleic acids Several other elements are needed in very smal amounts and are parts of enzymes and cofactors
Microorganisms require about ten elements in large quantities, because they are used to construct carbohydrates, lipids, proteins, and nucleic acids. Several other elements are needed in very small amounts and are parts of enzymes and cofactors. Concepts: Nutrient requirements
Macronutrients 95% or more of cell dry weight is made up of a few major elements: carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus, potassium, calcium, magnesium and iron. The first six(C, H, o,N, Pand s)are components of carbonhadrates, lipids, proteins and nucleic acids
Macronutrients • 95% or more of cell dry weight is made up of a few major elements: carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus, potassium, calcium, magnesium and iron. • The first six ( C, H, O, N, P and S) are components of carbonhadrates, lipids, proteins and nucleic acids
Trace elements Microbes require very small amounts of other mineral elements, such as iron, copper, molybdenum, and zinc these are referred to as trace elements. most are essential for activity of certain enzymes, usually as cofactors
Trace Elements Microbes require very small amounts of other mineral elements, such as iron, copper, molybdenum, and zinc; these are referred to as trace elements. Most are essential for activity of certain enzymes, usually as cofactors
Growth factors (1amino acids,(2)purines and pyrimidines,3)vitamins Amino acids are needed for protein synthesis purines and pyrimidines for nucleic acid synthesis. Vitamins are small organic molecules that usually make up all or part enzyme cofactors, and only very small amounts are required for growth
Growth Factors Amino acids are needed for protein synthesis, purines and pyrimidines for nucleic acid synthesis. Vitamins are small organic molecules that usually make up all or part enzyme cofactors, and only very small amounts are required for growth. (1)amino acids, (2) purines and pyrimidines, (3) vitamins
Nutritional types of microorganisms Sources of eners Major nutritional hydrogen/electrons, Representative type and carbon microorganisms Photoautotroph Light energy, inorganic Algae, Purple and green (Photolithotroph hydrogenelectron(H/e)bacteria, Cyanobacteria donor. cOz carbon source Photoheterotroph h Light energy, inorganic Purple nonsulfur bacteria Photoorganotropl H/e donor Green sulfur bacteria Organic carbon source Chemoautotroph Chemical energy source Sulfur-oxdizing bacteria ( Chemolithotroph (inorganic), Inorganic H/e Hydrogen bacteria donor, CO2 carbon source Nitrifying bacteria Chemoheterotroph Chemical energy source Most bacteria, fungi Chenoorganotroph) (organic), Organic H/e protozoa donor, Organic carbon source
Major nutritional type Sources of energy, hydrogen/electrons, and carbon Representative microorganisms Photoautotroph (Photolithotroph) Light energy, inorganic hydrogen/electron(H/e- ) donor, CO2 carbon source Algae, Purple and green bacteria, Cyanobacteria Photoheterotroph (Photoorganotroph) Light energy, inorganic H/e- donor, Organic carbon source Purple nonsulfur bacteria, Green sulfur bacteria Chemoautotroph (Chemolithotroph) Chemical energy source (inorganic), Inorganic H/edonor, CO2 carbon source Sulfur-oxdizing bacteria, Hydrogen bacteria, Nitrifying bacteria Chemoheterotroph (Chenoorganotroph) Chemical energy source (organic), Organic H/edonor, Organic carbon source Most bacteria, fungi, protozoa Nutritional types of microorganisms
Photoautotroph Algae. Cyanobacteria CO2+H2O Light+ Chlorophy+(CH20)+O2 Purple and green bacteria CO2+2H2S Light t bacteriochlorophyll,(CH20)+ H2O+ 2S Photoheterotroph Purple nonsulfur bacteria(rhodospirillum CO2+2CH3CHOHCH3 Light bacteriochlorophyll,(CH20) +H2o+2CH3 COCH3
Algae, Cyanobacteria CO2 + H2O Light + Chlorophyll （CH2O） +O2 Purple and green bacteria CO2 + 2H2S Light + bacteriochlorophyll（CH2O） + H2O + 2S Purple nonsulfur bacteria (Rhodospirillum) CO2 + 2CH3CHOHCH3 Light + bacteriochlorophyll（CH2O） + H2O + 2CH3COCH3 Photoautotroph: Photoheterotroph:
Properties of microbial photosynthetic systems Property cyanobacteria Green and Pu urple nonsulfur purple bacteriabacteria Photo-pigment Chlorophyll Bcteriochlorophyll Bcteriochlorophyll O2 production No No Electron donors H2O H2. h2S. s H2. h2s Carbon source CO2 CO2 Organic/CO Primary products ATP+ NADPH ATP ATP of energy conversion
Property cyanobacteria Green and purple bacteria Purple nonsulfur bacteria Photo - pigment Chlorophyll Bcteriochlorophyll Bcteriochlorophyll O2 production Yes No No Electron donors H2O H2, H2S, S H2, H2S, S Carbon source CO2 CO2 Organic / CO2 Primary products of energy conversion ATP + NADPH ATP ATP Properties of microbial photosynthetic systems
Chemoautotroph Bacteria Electron Electron Products donor acceptor alcaligens and H O H2O Pseudomonas sp Nitrobacter NO2 O NO3.H2O Nitrosomonas NH4 NO2.H2O Desulfovibrio H2 SO42- H2O. H2S Thiobacillus denitrificans So. H2S NO3 SO42N2 Thiobacillus ferrooxidans Fe O Fe3+ H2o Nitrifying bacteria 2NH4++302 2 NO2-+2 H20+4H++132 Kcal
Chemoautotroph: Nitrifying bacteria 2 NH4 + + 3 O2 2 NO2- + 2 H2O + 4 H+ + 132 Kcal Bacteria Electron donor Electron acceptor Products Alcaligens and Pseudomonas sp. H2 O2 H2O Nitrobacter NO2 - O2 NO3 - , H2O Nitrosomonas NH4 + O2 NO2 - , H2O Desulfovibrio H2 SO4 2- H2O. H2S Thiobacillus denitrificans S0 . H2S NO3 - SO4 2- , N2 Thiobacillus ferrooxidans Fe 2+ O2 Fe 3+ , H2O
