Water management

Question 1

catabolism of benzene derivatives

Answer 1

• microbes can break down aromatic pollutants from water
• benzoate undego aerobic catabolism to catechol

Question 2

microbial syntrophy

Answer 2

• syntrophy couples metabolism between two organisms such that overall yield is spontaneous
• normal aromatic products from petroleum are so stabel that their breakdown is positive delta g
• they are often thermodynamic extremophiles

Question 3

what are coliform bacteria

Answer 3

• lactose fermenting bacteria like e.coli or salmonella
• rod-shapped gram negative
• not usually pathogenic themselves, but large presence of them in feces indicates prescence of other pathogenic organisms

Question 4

how do we monitor coliform formation?

Answer 4

• total coliform test: test for microbes that report fecal contamination that is recent
• presence indicates recent fecal contamination
• sample -> serial dilution -> count

Question 5

how do we test for aggression of a lactose fermenter

Answer 5

• Eosin Methylene Blue Plate
• methylene blue interacts with gram (+) wall and breaks DNA/RNa
• eosin dye responds to changes in pH goes from colorless to purple to gree
• the more green, the more aggressive as a fermenter, the more pathogenic the gut bacteria

Question 6

what are 2 current clean water assays

Answer 6

1. EPA method 1603: collect sample, filter sample, and enrich and quantify
2. Most probable number method: collect sample, serial dilution, enrich and quantify

Question 7

what is the wastewater treatment process

Answer 7

1. wastewater
2. screening
3. sedimentation
4. anaerobic digestion and aerobic oxidation

Question 8

what is the process of aerobic oxidation

Answer 8

1. many species
2. metabolic types of bacteria vary - availability of substrates and nutrients
3. ideal microbes are selected for each substrate type
4. biofilms are produced by EPS (exopolysaccharide) and degrade most types of carbon compouds

Question 9

what is the process of anaerobic sludge

Answer 9

• microbes: fermenting bacteria and methanogenic archaea
• complex polymers are broken down by microbial enzymes and the monomers are fermented
• methanogens take acetate and H2 and CO2 into CH4 (methanogens)
• good source for biogas which is turned into energy

Question 10

what are excess contaminants still left in the water

Answer 10

• drugs and medicines: antibiotics, synthetic hormones, drugs
• xenobiotic chemicals: plastics, epoxides, synthetic dyes, pesticides, herbicides, fungicides
• heavy metals