文档介绍：Chapter 6 Microbial Growth and Metabolism
Microbial Nutrition
Microbial Growth
Metabolism
6 – 1. Microbial Nutrition
Nutrient requirements
Nutritional types of anisms
Uptake of Nutrients by the Cell
Culture Medium
Isolation of Pure Cultures
Outline:
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.
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) ponents 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.
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
Major nutritional type
Sources of energy,
hydrogen/electrons,
and carbon
Representative anisms
Photoautotroph
(Photolithotroph)
Light energy, anic hydrogen/electron(H/e-) donor, CO2 carbon source
Algae, Purple and green bacteria, Cyanobacteria
Photoheterotroph
(anotroph)
Light energy, anic H/e- donor,
Organic carbon source
Purple nonsulfur bacteria,
Green sulfur bacteria
Chemoautotroph
(Chemolithotroph)
Chemical energy source (anic), anic H/e- donor, CO2 carbon source
Sulfur-oxdizing bacteria, Hydrogen bacteria,
Nitrifying bacteria
Chemoheterotroph
(anotroph)
Chemical energy source (organic), Organic H/e- donor, Org