Phototrophic Bacteria

Question 1

Phototrophic bacteria

Answer 1

Majority of them are anoxygenic (do not produce oxygen through photosynthesis)
Are classified based on whether they use sulfur or not and then their colour
These use bacteriochlorophylls- purple, green, or blue
Use sunlight for energy

Question 2

Purple sulfur and non-sulfur bacteria

Answer 2

Colour from bacteriochlorophyll and carotenoids
Can be strict or facultative anaerobes
PSB - Use sulphites as their final electron donor (H2S) and produce sulfur
PNSB - Use hydrogen as their final electron donor

Question 3

Green sulfur and non sulfur bacteria

Answer 3

Colour from bacteriochlorophylls
GSB - use H2S and genus Chlorobium produces methane

GNSB - uses organic sulfites at low concentrations, or H2 gas and lives between 35 to 70 degree Celsius

Question 4

Cyanobacteria (blue green algae)

Answer 4

Colour from chlorophyll, phycocyanin and cyanophycin
Produces oxygen for the planet
Some are also able to fix nitrogen
undergo normal photosyntheses
Some make toxins for harmful humans / animals which causes tumors