1. Fundamentals of microbial ecology
CLS 416

2. Microbial ecology= Environmental microbiology:
Ecology: Is the study of the relationship of living organisms among each other & interactions or relations with their physical environment.
Microbial ecology= Environmental microbiology:
Distribution of microorganisms in the environment
Relationship with each other
Relationship with higher organisms
Relationship with the environment they live in
Ecosystem: Total communities in a habitat + physical environment they interact & live in.
Biosphere:The region of the earth inhabited by living organisms.
The largest ecosystem.

3. Components of the ecosystem
1- Abiotic components:
Include the non-living or physico-chemical factors that provide nutrients & energy to the biotic component.
The basic compounds and elements of the environment
2- Biotic components:
It consists of the living organisms of the environment,
It consists of populations that belong to different species inhabiting a common environment existing in association with each other.

4. Biotic component Producers:
- Self feeders and providers of food & energy to the
rest of organisms.
-Autotrophic bacteria: Produce organic materials from oxidation of
inorganic compounds.
-Photosynthesizers: Plants, algae, cyanobacteria.
Decomposers:
- live on dead decay bodies as a source of carbon. Putrification.
Fungi, bacteria and protozoa.
break large organic ,materials to smaller particles….. Inorganic compounds

5. Biotic component ----cont
Consumers:
-Heterotrophs: Can not produce organic compounds, but rely on the producers to do so.
- animals as primary consumers are herbivores.
secondary consumers are carnivores.
- nematodes
- protozoa
The activity of the 3 constitute the food chain or food web, that allows the exchange of food and energy so as recycling them in the ecosystem.

6. Evolutionary adapataion
Changes in the environment, as depletioin of nutrients, will lead to changes
in the biotic component where living organisims try to adapt to the change.
Phenotypic adaptation (physiologic)
- Physiologic change to adapt to temporary changes in the enviroment.
- Once the changes are over, organisms revert back to original state.
Genotypic adaptation (evolutionary)
- genetic changes might occur by mutation
- permanent changes.

7. Types of interactions Type of interaction Effect on Populations
Pop. A Pop. B
Neutralism No effect No effect
Commensalism Beneficial No effect
Synergism Beneficial Beneficial
Mutualism Beneficial Beneficial
Competition Detrimental Detrimental
Amensalism(antagonism) Detrimental No effect
Parasitism Beneficial Detrimental
Predation Beneficial Detrimental