BIOL 125 (Microbiology)
Chapter 7: Elements of Microbial Nutrition, Ecology, and Growth
– process by which chemical substances (nutrients) are acquired from the
environment and used for cellular activities (ex. growth and metabolism).
– must be provided to an organism through food that they consume.
They cannot be synthesized by the body.
Can be classified based on:
The amount required by the organism (macronutrients, micronutrients or
Macronutrients are required in large quantities; play principal
roles in cell structure and metabolism. Includes proteins,
carbohydrates, lipids, and nucleic acids; carbon, oxygen, and
Micronutrients or trace elements are required in small amounts;
involved in enzyme function and maintenance of protein
structure. Includes manganese, zinc, nickel, iron, etc.
Carbon presence (organic, inorganic).
Inorganic nutrients – molecule that contains a combination of
atoms other than the combination of carbon and hydrogen.
Derived from earth’s environment.
Organic nutrients – contain carbon and hydrogen atoms
combinations and are made by living things. Includes methane
), carbohydrates, lipids, proteins, and nucleic acids.
How Essential Nutrients Are Acquired.
Varies from organism to organism.
– use sunlight, inorganic nutrients found in the soil, and
atmosphere to make organic nutrients.
– obtain organic nutrients from live or dead material.
– otrain organic nutrients from their hosts.
Essential nutrients are derived from the earth’s environment: air, water, and soil.
These are constantly recycled to replenish the natural reservoir.
These include the sources for carbon, nitrogen, oxygen, hydrogen, sulfur,
trace metals, and growth factors.
CHEMICAL ANALYSIS OF MICROBIAL CYTOPLASM
96% of cell is composed of 6 elements (CHONPS) – carbon, hydrogen, oxygen, nitrogen,