Question

How can bacteria live anaerobically utilizing just amino acids (without access to sugars)

Answer 1

Ans. Some bacteria can convert some amino acids into pyruvate. For example, amino acid tryptophan can be converted into pyruvate by some anaerobic bacteria with the help of enzyme tryptophanase. Pyruvate is 3-Carbon compound produced at the end of glycolysis. Under normal aerobic condition, pyruvate produced at the end of glycolysis enter Citric acid cycle to generate ATP, NADH and FADH . Under anaerobic condition, pyruvate is converted to carbon dioxide and ethanol along with the synthesis of ATP(energy) during the fermentation process. As such energy is generated from amino acids via synthesis of pyruvate by anaerobic bacteria and they can survive without access to sugars.