Microbial environment

Question 1

Growth factros

Answer 1

Resources and growth conditions

Question 2

define niche

Answer 2

-Differences in type and quality of resources and the physiochemical conditions of a habitat define niche for each habitat

Question 3

Realized or prime niche

Answer 3

For each organisms, there exists at least one niche in which that organism is most successful

Question 4

Fundemental niche

Answer 4

Full range of environmental conditions under which an organism can exist

Question 5

Microenvironment

Answer 5

The immediate environmental surroundings of a microbial cell or group of cells
-soil particles contain many microenvironments

Question 6

Conditions of micro environment

Answer 6

Physiochemical conditions are subject to rapid change both spatially and temporarily
-Resources in natural environment are highly variable, and many M in nature face a feast or famine existence
-Growth rate is usually well below maximum growth rates found in lab

Question 7

NB of surfaces

Answer 7

_typically offer M greater access to nutrients and protection from predation and physiochemical disturbances
-Nutrients adsorb to surface
-Attachment to surface also offers cells a means to remain in a favorable habitat, modify habitat by their activities and not be washed away

Question 8

Biofilms

Answer 8

Assemblages of B cells adhered to a surface and enclosed in an adhesive matrix excreted by cels
-Matrix is a mixture of polysaccharides
-Biofilms trap nutrients for M growth and help prevent detachment of cells in flowing systems

Question 9

Reasons for biofilm formation

Answer 9

Self defence
-Biofilms resist physical forces that sweep away unattached cells, phagocytosis by immune system cells and penetration of toxins
Allow cells to remain in favorable niche
Allows B cells to live in close association with each other

Question 10

Biofilms and medical conditions

Answer 10

Peridontal disease
kidney stones
tuberculosis
Legionnaire’s disease
Staphylococcus infections

Question 11

Industrial settings and biofilms

Answer 11

BF can slow flow of liquids through pipelines/accelerate corrosion
-Surface colonisation and biodegredation of plastic alters surface chemistry, density, and sinking rates of microplates

Question 12

Treat biofilm

Answer 12

Use antibiofilm agents

Question 13

Microbial mats

Answer 13

-Very thick biofilms
-Built by phototophic and/or chemolithotrophic B
-Phototrophic mats contain filamentous cyanobacteria
-Cyanobacterial mats are complete ecosystems and have existed for 3.5 billion years
-Chemolithotrophic mats contian filamentous sulfur-oxidising B