Transcript Role of some fermentation parameters on cyclosporin A production

Role of some fermentation
parameters on cyclosporin A
production by a new isolate
of Aspergillus terreus.
Presented by
SEEMA RENU
Struture of Cyclosporin A
• Cyclosporin A is a cyclopeptide composed of 11 amino
acids
• It was first derived from submerged culture of aerobic
fungi identified as strains of Trichoderma polysporum.
• Trichoderma polysporum currently identified as
Tolypocladium inflatum also known as Tolypocladium
niveum.
• T. inflatum also produces numerous other cyclosporins all
composed of 11 amino acids differing from one another in
only one amino acid.
• For example the second amino acid in cyclosporine A is
alpha amino butyric acid whereas that in cyclosporine B is
alanine.
Discovery of Cyclosporin A
• It was discovered in the early 1970 by research workers at
Sandoz, Ltd in Basel, Switzerland during a search for
fungal metabolites with antibiotic properties.
• One of the metabolites released, known as 24-556 had
antifungal properties and very low toxicity toward the
mammalian cells when tested at Sandoz.
• The two components of 24-556 were termed as
Cyclosporin A and Cyclosporin B where as Cycloporin A
was much more active than Cyclosporine B.
• Human transplantation was first performed in 1978 using
cyclosporin A. Since then it has a major role in allogenic
transplantation and autoimmune diseases.
Mechanism of action
• Cyclosporin A works by selectively affecting the production
of T and B lymphocytes produced in the bone marrow and
thymus.
• Individuals with autoimmune diseases such as rheumatoid
arthritis produces excessive amount of toxic molecules
such as reactive oxygen intermediates that cause
inflammation in the joints.
• Cy A reduces the inflammation by selectively acting
against the production of these lymphocytes.
A macrophage engulfing a bacterium and
releasing packets of toxic molecules
(reactive oxygen intermediates) that breaks
down and destroy the bacterium
Cyclosporin A and kidney damage
• The widespread use of cyclosporin A
showed that it causes damage to the
kidneys.
• Studies proved that the damage can be
avoided by using cyclosporin A in lower
amounts and in conjunction with a steroid
called prednisone.
Fermentation parameters and
Cy A production by A. Terreus
• The conditions affecting the production of Cy A by A.
Terreus included the composition of the cultivation
medium, fermentation time course, inoculum nature,
medium volume, agitation rate and pH value.
• Different fungi were investigated for Cy A production.
• – sign indicated no production of Cy A, ++ showed a
moderate amount of Cy A production, whereas three +++
means higher production of Cy A as judged by the
darkness of the colony color.
The yield of the Cy
A increased as the
fermentation time
course increased.
The highest yield
of Cy A in mg/ml
was on the day 10.
The biomass yield
of A. terreus (g/l)
was kept on
decreasing after
day 10.
The best yield of
Cy A was obtained
by a 48-h-old
culture. As the age
increased
production of Cy A
start to decrease.
Maximum yield of Cy
A was obtained
when the volume of
the inoculum size
was 2ml/100ml.
The size of the
medium also affected
the production of Cy A.
A 250 ml Erlenmeyer
flask containing
production medium
equal to 100ml
afforded the highest
production of Cy A
The formation of Cy A
by A.terreus was also
affected by the
agitation rate.
The maximum
production was at 200
rpm
The production was maximum in an acidic
medium with a pH 5.3. Cy A production
decreased with an increase in pH.
Buffer is a partially neutralised acid that resists changes in
pH. The results showed that on using citrate buffer the
maximum yield (84.22 mg/L) of Cy A was obtained.
Increased pH also affected the texture of the fungal pellets
by making it weaker.
RESULTS
• The considerable amount of Cy A as a
secondary metabolite, was produced
under above described conditions, proved
A. terreus as a potential source.
• Still no data on its use for Cy A
production.
• It does used to extract lovastatin an agent
used to lower cholesterol.