Microbial Communities

Question 1

Examines interactions between species in groups over
a wide range of temporal and spatial scales, including
distribution, population dynamics, structure,
abundance, and demography

Answer 1

community ecology

Question 2

community ecology is also called

Answer 2

synecology

Question 3

important aspects of microbial communities

Answer 3

community boundary
community structure

Question 4

community strucrture can be described by

Answer 4

❑Species makeup
❑Species richness
❑Species relative abundance

Question 5

an assemblage of microbial cells that is irreversibly
associated (not removed by gentle rinsing) with a surface and
enclosed in a matrix of primarily polysaccharide material

Answer 5

biofilm

Question 6

Structured communities of
one or more species of
microorganisms.

Answer 6

biofilm

Question 7

biofilm produces a community of members of a matrix characterized by a ___

Answer 7

hydrogel

Question 8

a key stage in the biofilm lifecycle, involves the transition from initial microcolonies to a complex, three-dimensional structure, characterized by increased cell density and the production of an extracellular matrix (EPS

Answer 8

biofilm maturation

Question 9

adhesive structures in biofilm formation

Answer 9

PIA
eDNA
proteins

Question 10

disruptive factors in biofilm formation

Answer 10

proteases
nucleases
PSMs

Question 11

• considered a specialized type of
  biofilm.

Answer 11

biomats

Question 12

range from several millimeters to a
centimeter thick, and are vertically
stratified into distinct layers versus
biofilms which are typically one to
several cell layers thick

Answer 12

biomats

Question 13

microbial
groups are tightly compressed into a
thin mat of biological activity)

Answer 13

biomats

Question 14

commonly associated with aquatic
habitats, including hot springs,
hypersaline ponds, and intertidal
coastal zones and oligotrophic
environments

Answer 14

biomats

Question 15

first layer of biomat

Answer 15

microalgae

Question 16

second layer of biomat

Answer 16

cyanobacteria and diatom species
(oxygenic phototrophs, aerobic heterotrophs

Question 17

3rd layer in biomat

Answer 17

purple sulfur and green sulfur bacteria (anoxygenic phototrophs
anaerobic heterotrophs)

Question 18

fourth layer in biomat

Answer 18

sulfate reducers
methanogens
iron sulfide rich sediments

Question 19

Sedimentary layer, CH4 and H₂S formation

which layer

Answer 19

sulfate layers, methanogens, iron sulfide rich sediments

Question 20

• It is the regulation of gene expression in response to
  fluctuations in cell-population density.

Answer 20

quorum sensing

Question 21

• Quorum sensing bacteria produce and release chemical signal
  molecules called

Answer 21

autoinducers

Question 22

that increase in concentration
as a function of cell density

Answer 22

autoinducers

Question 23

gene expression produces

Answer 23

rna and protein

Question 24

study quorum sensing and explain it

Answer 24

Lux Quorum Sensing in Vibrio fischeri
Autoinducer Production:

The process begins with the production of an autoinducer molecule, specifically N-acyl homoserine lactone (AHL), synthesized by the enzyme LuxI.

As the bacterial population grows, the concentration of AHL increases in the environment.

Detection and Activation:

When the concentration of AHL reaches a threshold level, it binds to the LuxR protein, a transcriptional activator.

The LuxR-AHL complex then binds to the promoter region of the lux operon, activating the transcription of genes responsible for bioluminescence.

Bioluminescence:

The lux operon includes genes such as luxA and luxB, which encode the α and β subunits of luciferase, the enzyme that catalyzes the light-emitting reaction.

Additional genes, luxC, luxD, and luxE, are involved in synthesizing the fatty aldehyde substrate required for the bioluminescent reaction.

Regulation and Efficiency:

The system ensures that bioluminescence occurs only at high cell densities, making it an energy-efficient process.

This mechanism allows Vibrio fischeri to produce light in a synchronized manner, which is beneficial for symbiotic relationships, such as with the Hawaiian bobtail squid

Question 25

Quorum sensing is also important in:

Answer 25

toxin production antibiotic resistance virulence factor population competence conjugation sporulation motility

Question 26

* are signaling molecules that are produced in response to changes in cellpopulation density

Answer 26

autoinducers

Question 27

(as the density of quorum sensing bacterial cells increases so does the concentration of the ____)

Answer 27

autoinducers

Question 28

* allow bacteria to communicate both within and between different species.

Answer 28

autoinducers

Question 29

This communication alters gene expression and allows bacteria to mount coordinated responses to their environments, in a manner that is comparable to behavior and signaling in higher organisms

Answer 29

autoinducers

Question 30

is the enzymatic degradation of molecules used by bacteria for synchronizing their behavior within communities

Answer 30

quorum quenching

Question 31

has attracted wide attention due to its potential to inhibit biofilm formation and suppress the production of virulence factors.

Answer 31

quorum quenching

Question 32

* Microorganisms rapidly recolonize these barren surfaces, coming from surrounding areas, blown in on air currents, carried in on animals and plants returning to disturbed areas called

Answer 32

immigration and recruitment

Question 33

recovering from remnant populations

Answer 33

regrowth

Question 34

* Natural environment where colonization and recolonization can occur

Answer 34

* Freshly cooled lava * Newborn’s GIT system * Emergent leaves

Question 35

artificial environments where microbes can colonize and recolonize

Answer 35

Medical devices * Implants * Transplants * Built environments

Question 36

is the number of different species in an area, it is a key measurement used to assess the variety of species in an ecosystem

Answer 36

species diversity

Question 37

is the number of different species in a given area or ecosystem

Answer 37

species richness

Question 38

is the number of individuals of a species in a given area.

Answer 38

species abundance

Question 39

* the proportion of a particular type of organism in a community relative to the total number of organisms in that community

Answer 39

relative abundance

Question 40

is the difference between the number of microbes seen under a microscope and the number that can be grown in a lab

Answer 40

thre great plate cont anomaly

Question 41

Microbes play multiple important functions in Earthian processes

Answer 41

element cycling decomposition infections

Question 42

s can be revealed in phylogenetic trees - getting a handle on this vast diversity can be accomplished through the use of diversity indices

Answer 42

evolutionary events

Question 43

* Is a quantitative measure that reflects how many different types (such as species) there are in a dataset (a community).

Answer 43

diversit indices

Question 44

best example of diversity indices are

Answer 44

shannon-weiner diversity index simpson diversity index

Question 45

* It is the movement of organisms across space and time.

Answer 45

dispersal

Question 46

It is the process by which the mix of species and habitat in an area changes over time

Answer 46

ecological succession

Question 47

occurs in newly exposed or created areas without life (like volcanic rock),

Answer 47

primary succession

Question 48

happens in areas where life existed but was disrupted, with soil already present.

Answer 48

secondary succession

Question 49

An ecosystem capable of returning to its equilibrium state after a perturbation or does not experience unexpected large changes in its characteristics across time.

Answer 49

ecological stability

Question 50

refers to an ecosystem's ability to remain relatively unchanged when faced with disturbances

Answer 50

resistance

Question 51

refers to an ecosystem's capacity to absorb disturbances and maintain its fundamental functions and structures, ultimately returning to its pre-disturbance state.

Answer 51

resilience

Question 52

efers to the degree to which ecosystem properties or functions remain consistent over time, often measured as the inverse of the coefficient of variation

Answer 52

temporal stability

Question 53

involves assisting ecosystems to return to a stable state after damage or degradation, whether through natural processes or active intervention

Answer 53

ecological stability