文档介绍：Chapter3 Microbial nutrition
requirement
types of anisms
of nutrients
media
Microbial Growth Conditions
1. Macronutrients
2. Micronutrients
3. Growth factors
4. Environmental factors: temperature; pH; Oxygen et al.
anisms 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
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 anisms for catabolism and anabolism.
contaminants in water, glassware, and regular ponents often are adequate for growth.
Growth Factors
Amino acids are needed for protein synthesis,
purines and pyrimidines for nucleic acid synthesis.
Vitamins are anic 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
Extraordinary flexibility:
No naturally anic molecule cannot be used by some anism. eg. Paraffin(石蜡), rubber.
Omnivores: use over 100 different pounds.
Fastidious: catabolize only a few pound
Relatively indigestible human-made substances are metabolized plex populations of anisms.
Major nutritional type
Sources of energy,
hydrogen/electrons,
and carbon
Rep