2. ESSENTIALS OF MICROBIOLOGY (BY STAURT
HOGG)
Essentials of industrial microbiology(by
Basanta Rai)
3. An antibiotic is a microbially produced substance (or a
synthetic derivative) that has antimicrobial properties.
They may either kill or inhibit the growth of bacteria.
Discovered by : Alexander Fleming in 1928.
Antibiotics can be bacteriostatic or bactericidal.
The main classes of antibiotics:
Aminoglycosides
Cephalosporins
Fluoroquinolones
Macrolides
Penicillins
Tetracyclines
4. All antibiotics have the common property of
interfering in some way with a normal, critical
function of the target bacterial cell. The most
commonly used antibiotics exert their effect
by one of the following methods: 1 Inhibition
of cell wall synthesis (group I)
2 Disruption of cell membranes (group II)
3 Interference with protein synthesis (group
III)
4 Interference with nucleic acid synthesis
(group IV)
5. Erythromycin-like antibiotics are also known as
macrolides.
Macrolides belong to the polyketide class of natural
products.
Macrolide antibiotics are are hydrophobic, basic
compound.
Macrolide antibiotics slow the growth of, or sometimes
kill sensitive bacteria by reducing the production of
important proteins needed by the bacteria to survive.
The commonly used macrolides are:
• Erythromycin
• Clarithromycin
• Roxithromycin
• Azithromycin
6.
7. Erythromycin was discovered in 1952 by McGuire
and coworkers from a strain of Streptomyces
erythreus.
It is a broad spectrum antibiotic.
Erythromycin can be taken orally and has a
similar spectrum of activity to penicillin G; it is
often used instead of penicillin in the treatment
of staphylococcal and streptococcal infections in
children. It is particularly appropriate for this
application as it is one of the least toxic of all
commonly used antibiotics.
It is poorly soluble in water.
Trade name is E-mycin or Erythrocin
8. ERYTHROMYCIN A ERYTHROMYCIN B
The B analog is more acid stable but has only about
80% of the activity of erythromycin.
9. Erythromycin displays a bacteriocidal activity
particularly at higher concentrations.
It prevents the growth of bacteria by
inhibiting their protein synthesis.
Erythromycin binds to 50S ribosomal subunit.
Binding site near the peptidyltransferase
center.
This binding blocks thee exit of the growing
peptide thus inhibiting the translocation of
the peptides.
Peptide chain elongation is also prevented.
10.
11. Erythromycin is produced from Streptomyces
and Micromonospora.
Erythroymycin is produced mainly by
submerged fermentation.
A vessel called bioreactor contain nutreint
media or culture media
The steps for erythromycin production are as
follows:
12. The process begins with the isolation of a
suitable strain of streptomyces erythraeus
from natural sourses such as soil
Once isolated the strains are screened for
their abillity to produce erythromycin
effeciently.
13. ◦ Inoculum is the population of microorganisms
or cells that is to be fermented.
◦ Inoculum is prepared from suspension of at
least 108 cells/ml.
◦ Culture media for S.erythraeus is done on
tryptone agar slant.
◦ Inoculum development is a crucial step in the
production of eeythromycinand involves the
preparation of a hig quality starter culture
media to initiate fermentation.
15. Fermentation is carried out in stirred tank
fermenter.
It should have proper aeration and agitation, pH,
temperature, viscosity and dissolved oxygen
concentration.
Temp: Fermentation temperature is 33oC.
Duration: The length of fermentation is 3-7 days.
Production of Erythromycin production occurs
when froth reaches stationary phase.
Addition of n-propanol as precursor increases
the production of erythromycin.
16.
17. Througout fermentationprocess,samples are
periodically withdrawn from the fermentor to
monitor cell growth ,erythromycin production
and other relevant parameters.
Samples maybe analyzed using various
analytical techniques such as high
performance liquid chromatography(HPLC) in
order to quantify erythromycin levels.
18. As the fermentation occur ,the product that
forms(containing micro-organism,antibiotic
,nutreints etc) is called fermentation broth.
This broth undergoes filtration process for
extraction of antibiotic.
Ultrafiltration is used to filter the microbial
cells from the broth leaving behind a clarified
solution of erythromycin.
And we obtain filtrate.
19. The extracted erythromycin is then purified
further to remove any impurities.
This process may involve:
1.crystallization
2.chromatography
20. Finally the purified erythromycin is
formulated into various pharmaceutical forms
such as:
Capsules
Tablets
Suspensions
Ointments etc
