Anaerobic fermentation often provides CO2, which can be used by ________ as an electron acceptor for energy.
A. acetogens
B. methanotrophs
C. methanogens
D. acetogens and methanogens
Answer:D
Anaerobic fermentation often provides CO2, which can be used by ________ as an electron acceptor for energy.
A. acetogens B. methanotrophs C. methanogens D. acetogens and methanogens