华中农业大学：《食品微生物学》课程PPT教学课件（Food Microorganism）Chapter 6 Microbial Growth and Metabolism

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 • Nutrient requirements • Nutritional types of microorganisms • Uptake of Nutrients by the Cell • Culture Medium • Isolation of Pure Cultures Outline:

6 – 1. Microbial Nutrition • Nutrient requirements • Nutritional types of microorganisms • Uptake of Nutrients by the Cell • Culture Medium • Isolation of Pure Cultures Outline:

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

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, P and 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 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

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

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/e￾donor, CO2 carbon source Sulfur-oxdizing bacteria, Hydrogen bacteria, Nitrifying bacteria Chemoheterotroph (Chenoorganotroph) Chemical energy source (organic), Organic H/e￾donor, Organic carbon source Most bacteria, fungi, protozoa Nutritional types of microorganisms

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/e￾donor, CO2 carbon source Sulfur-oxdizing bacteria, Hydrogen bacteria, Nitrifying bacteria Chemoheterotroph (Chenoorganotroph) Chemical energy source (organic), Organic H/e￾donor, Organic carbon source Most bacteria, fungi, protozoa Nutritional types of microorganisms

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:

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:

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

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: 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

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