《微生物学》课程教学课件（PPT讲稿）Chapter3 Microbial nutrition

Chapter3 Microbial nutrition 1. Nutrient requirement 2.Nutritional types of microorganisms 3.Uptake of nutrients 4. Culture media

Chapter3 Microbial nutrition 1.Nutrient requirement 2.Nutritional types of microorganisms 3.Uptake of nutrients 4.Culture media

Microbial growth Conditions I Macronutrients 2. Micronutrients 3. Growth factors 4. Environmental factors: temperature; pH; Oxygen et al Nutrient requirements Microorganisms require a bout 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

Microbial Growth Conditions 1. Macronutrients 2. Micronutrients 3. Growth factors 4. Environmental factors: temperature; pH; Oxygen et al. 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. Nutrient requirements

Microbial nutrition Nutrients: Substances in the environment used by organisms for cata bolism and anabolism Macronutrients: required in large amounts, including carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus (Components of carbohydrates, lipids, proteins, and nucleic acids ) potassium, calcium, magnesium and iron(cations and part of enzymes and cofactors). 2. Micronutrients: 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 contaminants in water, glassware, and regular media components often are adequate for growth

Microbial Nutrition 1. Macronutrients: required in large amounts, including: carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus (Components of carbohydrates, lipids, proteins, and nucleic acids ); potassium, calcium, magnesium and iron (cations and part of enzymes and cofactors). 2. Micronutrients: 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. Nutrients: Substances in the environment used by organisms for catabolism and anabolism. contaminants in water, glassware, and regular media components often are adequate for growth

Growth factors ()amino 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

Requirement for carbon, hydrogen and oxygen Carbon sources: heterotrophs:"CHO autotrophs: CO2 Xtraordinary flexibility No naturally occurring organic molecule cannot be used by some microorganism eg Paraffin( st), rubber Omnivores: use over 100 different carbon compounds Fastidious: catabolize only a few carbon compound Relatively indigestible human-made substances are metabolized by complex populations of microorganisms

Requirement for carbon, hydrogen and oxygen Carbon sources: heterotrophs: “CHO” autotrophs: CO2 Extraordinary flexibility: No naturally occurring organic molecule cannot be used by some microorganism. eg. Paraffin（石蜡）, rubber. Omnivores: use over 100 different carbon compounds. Fastidious: catabolize only a few carbon compound Relatively indigestible human-made substances are metabolized by complex populations of microorganisms

Nutritional types of microorganisms Sources of energy, Major nutritional hydrogen/electrons,Representative type and carbon microorganisms Photoautotroph Light energy, inorganic Algae, Purple and green Photolithotroph) hydrogen/electron(H/e)bacteria, Cyanobacteria donor cO carbon source Photoheterotroph Light energy, inorganic Purple nonsulfur bacteria, He- donor (Photoorganotroph) 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 Chemoheterotropl h Chemical energy source Most bacteria, fungi Chemoorganotrophy) (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/e￾donor, CO2 carbon source Sulfur-oxdizing bacteria, Hydrogen bacteria, Nitrifying bacteria Chemoheterotroph (Chemoorganotroph) Chemical energy source (organic), Organic H/e￾donor, Organic carbon source Most bacteria, fungi, protozoa Nutritional types of microorganisms

Photoautotroph: Algae, Cvanobacteria CO2+H20 Light+ Chlorophyll(CH20)+O2 Purple and green bacteria CO2+2H2S Light bacteriochlorophyll,(CH20)+ H20+2S Photoheterotroph: Purple nonsulfur bacteria( rhodospirillum CO2+2CH3CHOHCH3 Light bacteriochlorophyll,(CH2O) + H20+ 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 Purple nonsulfur purple bacteria bacteria Photo-pigment Chlorophyll Bcteriochlorophyll Bcteriochlorophyll O production Y No Electron donors H2O H2 H2S. s H2 h2S. s 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 O H2O Pseudomonas sp Nitrobacter NO2 NO3. H2O Nitrosomonas NH4 O2 NO2.H20 Desulfovibrio 2 SO42 H2o. h2s Thiobacillus denitrificans So H2S NO3 SO42N2 Thiobacillus ferrooxidans O Fe3+ H2O Nitrifying bacteria 2NH4++3O2 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

Nutritional types of microorganisms PhototrophS: use light as energy source Chemotrophs: obtain energy from the OXidation of chemical compounds Lithotrophs: use reduced inorganic substances as their electron source Organotrophs: exteact electrons from organic compounds

Nutritional types of microorganisms • Phototrophs: use light as energy source. • Chemotrophs: obtain energy from the oxidation of chemical compounds. • Lithotrophs: use reduced inorganic substances as their electron source. • Organotrophs: exteact electrons from organic compounds