Biochemical activity of bacteria
Carbohydrate metabolism and
terminal oxidation
Arash Ravandi
• All bacteria utilize energy sources to produce
ATP.
• Source of energy for bacteria:
C: from sugar and lipid → energy &
biosynthesis
N: from protein → biosynthesis
O: from air →energy
• Heterophilic bacteria use carbohydrate as
energy source, they use enzymes to utilize
simple sugars like glucose and
monosaccharides
• Major carbohydrate metabolism pathway:
• 1.Embden-meyerhof-parnas (EMP)
glycolysis
• 2.Entner-Doudoroff (ED)
• 3.Penthose phosphate (PP)
• 4.Kreb´s cycle
• Each bacteria has it´s own collection of
enzymes
this is useful to identify bacterial species by
checking products from the oxidation and
fermentation of these carbohydrates.
fermentation kit
Detection:
• PH indicator: to detect metabolic acids
that produce by bacteria after oxidation
and fermentation of sugars. Example:
Phenol red
• Reagent: after bacteria have grown it
reacts with specific byproduct or
intermediates in the metabolic pathway.
• Gas production, Example: Durham tubes
Durham tube
PH indicator
• Metabolic activity test:
ATP assay: measure ATP by luciferase
system