Lecture 27 - Environmental Microbiology

Question 1

What is the imporance of “crusts”?

Answer 1

crusts can help hold soil in place which prevents erosion + stabilizes soil enough for water to get in and allow some plants to grow

Question 2

How many bacteria can be found in 1 g of soil?

Answer 2

100 million - 1 billion

Question 3

The center of a compost pile is ____.

Answer 3

Hot
(up to 60 C)

Question 4

Streptomyces is an important source of _______.

Answer 4

antibiotics

Question 5

How can camels find water from so far away?

Answer 5

They can smell the chemicals produced by streptomyces.

Question 6

gangrene

Answer 6

soft tissue death

Question 7

ischemia

Answer 7

inadquate blood supply

Question 8

Clostridium perfringens can cause _____.

Answer 8

Gangrene

Question 9

Biogeochemcial Cycles

Answer 9

how elements are cycled between living and non-living parts of the biosphere

Question 10

How is CO2 in the air used?

Answer 10

used by plants, algae and cyanobacteria for photosynthesis to make sugar and water

Question 11

Fixation of CO2

Answer 11

CO2 is fixated into sugars in the tissues of plants, algae and cyanobacteria

Question 12

Plants and Animals both release CO2 back into the air through what process?

Answer 12

Cellular Respiration

Question 13

Decomposition of dead plants and animals release ____ into the air.

Answer 13

CO2

Question 14

Is CO2 dissolved in water for use by aquatic life?

Answer 14

yes

Question 15

Burning wood and fossil fuesl releases ____ into the air.

Answer 15

CO2

Question 16

What is the most abundant molecule in the air?

Answer 16

Nitrogen (N2)

Question 17

Fixation of Nitrogen

Answer 17

N2 is fixated to NH3

Question 18

N2

Answer 18

free nitrogen gas

Question 19

NH3

Answer 19

ammonia

Question 20

Nitrification

Answer 20

NH3 is converted into NO2- then NO3-

Question 21

NO2-

Answer 21

Nitrite

Question 22

NO3-

Answer 22

Nitrate

Question 23

Denitrification

Answer 23

Nitrate (NO3-) is converted back into free nitrogen gas (N2)

Question 24

Legumes and Rhizobium are important for ______.

Answer 24

Nitrogen Fixation

Question 25

Non-Symbiotic Fixating Microbes

Answer 25

microbes which can fixate nitrogen, but live freely in the soil

Question 26

Symbiotic Fixating Microbes

Answer 26

microbes which can fixate nitrogen and live inside of plant roots (i.e. Rhizobium & Bradyrhizobium live in the roots of legumes)

Question 27

Xenobiotics

Answer 27

synthetic chemicals not readily degraded by microbes

Question 28

bioremediation

Answer 28

the breakdown and elimination of environmental contaminants by living organisms

Question 29

3 Variables Influencing Bioremediation

Answer 29

1. Temperature
2. Amount of O2 available
3. Concentration of Potentially Limiting Nutrients

Question 30

Biostimulation

Answer 30

the addition of nutrients to a contaminated site to stimulate the microbes doing the bioremediation

Question 31

Bioaugmentation

Answer 31

the use of pollutant-acclimated microbes or GMOs for bioremediation

Question 32

GMO

Answer 32

genetically modified organisms

Question 33

aeration

Answer 33

mixing air into water

Question 34

coagulation and flocculation

Answer 34

removes large numbers of viruses and bacteria in water by adding aluminum sulfide which will coagulate and cause clumps which will then settle to the bottom of the tank and leave cleaner water at the top

Question 35

List the Step of Treating Water

Answer 35

Water from a reservoir is aerated then moved into a mixing chamber.
Aluminum Sulfide is added to the the water for coagulation and flocculation where the larger, coagulated particles will settle to the bottom of a settling tank, leaving clearer water on top. The water on top is then filtered.

Question 36

Membrane Filtration of Water can Effiectively Eliminate

Answer 36

Giardia and Cryptosporidium

Question 37

3 Methods to Disinfect Water

Answer 37

• Chlorine
• UV Light
• Ozone Treatment

Question 38

BOD

Answer 38

Biochemical Oxygen Demand

Question 39

Biochemical Oxygen Demand Test

Answer 39

measures the amount of organic waste in water by measuring the amount of oxygen that has been used over the course of 5 days

Question 40

Eutrophication

Answer 40

water pollution from fertilizers/sewage may encourage algal blooms at the expense of animal life

Question 41

How is sewar water treated?

Answer 41

1. Large contaminants (sludge) are removed from sedimentation tanks
2. Primary effulent undergoes oxidation and then is cycled through a settling tank a couple of times
3. Water is filtered to form secondary effluent
4. Water is disinfected then released

Question 42

Trickling Filter

Answer 42

sewage water is sprayed over zoogleal biofilm-covered rocks which oxidize the organic material in the water

Question 43

Rotating Biological Contactor

Answer 43

Massive Disks Covered in Zoogleal Biofilm rotate through water to oxidze the organic material

Question 44

How is Sludge Digested?

Answer 44

Anaerobic microorganisms are added to break down the slude. Methane is released in the process.

Question 45

Explain How Septic Tank Systems Work

Answer 45

Water goes from the house to the septic tank. Solids settle out. Effluent flows out of the septic thank into a leeching field where microbes in the soil can degrade organic material in the effluent.

Question 46

Puprose of Tertiary Water Treatment

Answer 46

follows disinfection to remove remaining BOD, N, and P.

Question 47

What happens to a retired landfill?

Answer 47

It is converted into a bioreactor to speed up the rate of decomposition of materials by about 30%.