Module 4 - Microbial Ecosystems Flashcards
The specific functional role of an organism within an ecosystem is called?
Niche
What are the 3 factors pertaining to resources that help define a niche?
- Type
- Quality
- Quantity
What is the general rule in ecology?
No two populations of organisms can occupy the same niche and co-exist sustainably
Which archaeal and bacterial pair can coexist stably within the same gut habitats?
Methanobrevibacter smithii and E.coli
E.coli is the … in the colon
Fermenter
M. smithii is a … in the colon
Methanogen
Structured communities held together by extracellular polysaccharides are called?
Biofilms
How does biofilm growth provide an advantage for microorganisms?
Nutrients bind to solid surfaces; enables higher cell concentrations
What are the first microorganisms adhering to a surface? Give an example
- Appendaged bacteria
- Caulobacter or Hyphomicrobium
Species that divide and form microcolonies are called?
Primary colonizers
Species that join the growing biofilms are called?
Secondary colonizers
What forms a gel-like matrix that is important for biofilm formation?
Exopolyssacharides (EPS)
What are the functions of the gel-like matrix?
- Aids in the formation of water-filled channels
- Facilitates the transport of nutrients and waste through the biofilm
Using a culture medium and conditions designed to favor the growth of a particular microorganisms is called?
Cultivation-Dependent Techniques
What is the name of the aerobic N2-fixing bacteria?
Azotobacter
Characterizing inhabitants of microbial ecosystems, including microorganisms that we cannot grow readily are called?
Cultivation-Independent Techniques
Minerals, gases, and water are known as what kind of factors?
Abiotic factors
How do organisms become specialized for their prime niches?
- Evolutionary pressures of selection
- Competition
Why can’t two populations of organisms occupy the same niche?
One population will always outcompete
What do we call environments in which conditions change over short distances?
Microenvironments
What experiment demonstrated the importance of EPS production?
EPS production by Escherichia coli K12 during biofilm formation
Which bacterium is use to understand the practical concerns associated with biofilms?
Pseudomonas aeruginosa