Download Microbial Metabolism Lipids and Proteins - ASAB-NUST

LECTURE 13:
Microbial Metabolism
Lipids and Proteins
Microbiology and Virology; 3 Credit hours
Atta-ur-Rahman School of Applied Biosciences (ASAB)
National University of Sciences and Technology (NUST)
LIPID CATABOLISM
Fatty Acid β-Oxidation
Fatty Acid β-Oxidation
Fatty Acid β-Oxidation
Fatty Acid β-Oxidation
Protein and Amino Acid Catabolism
• Some bacteria and fungi particularly
pathogenic, food spoilage, and soil
microorganisms can use proteins as their
source of carbon and energy.
• They secrete protease enzymes that hydrolyze
proteins and polypeptides to amino acids,
which are transported into the cell and
catabolized
Protein and Amino Acid Catabolism
• The first step in amino acid use is deamination,
the removal of the amino group from an amino
acid. This is often accomplished by
transamination.
• The amino group is transferred from an amino
acid to an α keto acid acceptor.
• The organic acid resulting from deamination can
be converted to pyruvate, acetyl-CoA, or a TCA
cycle intermediate and eventually oxidized in the
TCA cycle to release energy
Protein and Amino Acid Catabolism
The α amino group (blue) of alanine is transferred to the acceptor α
ketoglutarate forming pyruvate and glutamate. The pyruvate can be catabolized
in the ricarboxylic acid cycle