carbohydrate fermentation

Question 1

what are the 6 fermentative acids

Answer 1

lactic acid, ethanol, mixed acids,

butyric, propionic, homoacetic

Question 2

what fermentations have

Answer 2

products get fermented by a second organism
some have ion gradients (H+ or NA+) as the basis of their energetics
· With some subtrates, inadequate energy is released to couple to ATP synthesis directly by substrate level phosphorylation

Question 3

describe what succinate fermentation by propionigenium modestum

Answer 3

Chemostatic ATP formation results from Na pump (decarboxylation of organic acids)
· Ex. Decarboxylation of succinate is coupled to the export of sodium across the cytoplasmic membrane
· Oxalate decarboxylation to formate results in the build-up of a PMF from the exportation of formate

Question 4

what is happening in the aerobic food chain?

Answer 4

AA, pyridines, purines and carbs into organic acids and alcohols
then covert CO2, H2 and acetate into CH4 and CO2

Question 5

what is happening in the Proionate Fermentation by the Succinate-Propionate Pathway

Answer 5

yields more ATP than the acrylate pathway (per molecule of propionate formed)
· ex. Propionibacterium: G positive anaerobic, non-sporeforming, non motile, pleomorphic rod
· (Swiss cheese production)

Question 6

Fermentation pathway of Clostridium propionicum

Answer 6

1. lactate oxidized to pyruvate
2. pyruvate oxidized to acetyl-coA and CO2
3. acetyl-CoA converted viz acetyl-P
4. to acetate and ATP
5. lactate acquires a CoA from propionly-CoA*
6. lactyl-CoA is dehydrated to acrylyl-CoA
7. acrylyl-CoA is reduced to propionyl-CoA
   * Propionate is produced during the CoA transfer step (5) catalyzed by CoA transferase

• bacteria use a standard method for making ATP under anaerobic conditions
• production of acetate generates two moles of ATP per mole of acetate if bacteria are growing on glucose and using the EMP pathway

Question 7

Acetate fermentation

Answer 7

-acetogenic bacteria from different substrates
Eg: Desulfototmaculum thermobencocium from pyruvate: clostridium theroaceticum from CO2

• More acetate
• • figure of oxidation steps and reduction steps in this pathway
• Coupled fermentation pathway and they are sharing things and making P

Question 8

Lactate Fermentation

Answer 8

• homofermentative and heterofermentative
• Heterogenous group of aerotolerant anaerobes, fermenting glucose to lactate as either the only or major product

Eg: lactobacillus and strep, lec (yogurt, pickles and sauerkraut) – in the GI tract

Question 9

Facultative-

Answer 9

use O2

Question 10

Aerotolerant anaerobe

Answer 10

able to detoxify intermeddles and not use O2

Question 11

homofermentative

Answer 11

glucose and lactic acid

Question 12

heterfermentative

Answer 12

CO2, lactic acid and ethanol

Question 13

Mixed acid fermentation

Answer 13

• Products: succinate, lactate, acetate, ethanol, formate, CO2, H2S gas
• Enteric bacteria- facultative anaerobes (Eg. Escherichia, Salmonella and Shigella)
• • on board: sigma protobacteria and enterobacteria

Question 14

what is a syntrophisum

Answer 14

they are obligate anerobes that preform nitrification