LAB 1 sulfur cycle

Question 1

what role does sulfur play in bacteria

Answer 1

play a structural role in amino acids and is also largely involved many vitamins and cofactors

Question 2

what is the more abundant organic for of sulfur

Answer 2

dimethyl sulfide

Question 3

what is the more abundant inorganic for of sulfur

Answer 3

Found trapped in sediments and rocks

Question 4

what is sulfur reduction

Answer 4

the conversion of sulfate (SO4) to hydrogen sulfide (H2S)
this process is anaerobic often done by Desulfivibrio

Question 5

what is sulfur oxidation

Answer 5

hydrogen sulfide(H2S) , elemental sulfur(S) or Sulfite (SO3-2) are all converted to sulfate (SO4-2)

this process releases protons thus lowering the pH of the medium.

some sulfur oxidizing bacteria are acidophilic such as acidithiobacillus

Question 6

what broths were used in this experiment and what were they trying to accomplish

Answer 6

There were 2 broths which were used in this experiment Starkey broth and thiosulfate broth both of which use a purple pH indicator which changes the broth colour to yellow at pH below 5.4
Starkey broth contained S as its Sulfur source and thiosulfate broth contained sodium thiosulfate as its sulfur source

the goal was to inoculate the broths with sludge and isolate different bacteria based on what types of sulfur they are able to metabolize then observe and record the morphological differences between the 2 through gram staining.