microbial production of antibiotics penicillin and streptomycin
1. MICROBIAL PRODUCTION OF ANTIBIOTICS
(PENICILLIN AND STREPTOMYCIN)
Subhananthini Jeyamurugan,
18py17, M.Sc., microbiology.
Ayya nadar Janaki ammal college Sivakasi.
2. ANTIBIOTIC PRODUCTION
Antibiotics are metabolites having preferential antimicrobial activity.
Therefore, they are widely used for curing of human ailments caused by
microorganisms.
Antibiotic compounds are used either in their natural form or as semi synthetic
derivatives; the latter arc usually produced by isolating the antibiotic nucleus
and subjecting it to chemical modification. Antibiotics are produced by both
fungi and bacteria.
Antibiotics are generally produced in stainless steel fermenters (30,000-200,000
1 medium volume) used in the batch or fed-batch mode.
4. PENICILLIN:
Penicillin is an antibiotic produced by microorganisms.
Generally the penicillin antibiotic is produced by some Actinomycetes
and some filamentous fungi.
It is used against Gram positive bacteria as well as high dosage can be
used against Gram negative bacteria.
Penicillin is not harmful to plants, animals or human beings except in
some cases of allergies.
6. MODE OF ACTION
The penicillin antibiotic acts on the cell wall synthesis of growing Gram positive
bacteria.
Penicillin is a β lactamase antibiotic.
Beta lactam ring attaches to the DD trans peptidase.
It results in inhibition of formation of cross linkage in the cell wall
The growth and development of cell is stopped.
Results in protoplast.
Whereas gram negative cell do not loss its cell wall completely so called as spheroplast.
After inhibition of cell wall the protoplast and spheroplast are formed.
Due to increase in osmotic pressure the cell undergoes its lysis.
7. PRODUCTION OF PENICILLIN:
Penicillin fermentation is carried out anaerobically by
submerged aerated fermentation process.
Fermentation medium
Fermentation organism
Inoculum preparation
Fermentation process
Recovery and Harvest of penicillin.
8. FERMENTATION MEDIUM:
Carbon source – Glucose, Lactose and Sucrose.
Nitrogen source – Ammonium sulphate, Ammonium acetate, Ammonium lactate.
Amino acids – Corn steep liquor.
Precursors for penicillin G – phenylacetic acid.
Precursors for penicillin X – Hydroxyphenylacetic acid.
Precursors for penicillin V – Phenoxyacetic acid.
9. FERMENTATION ORGANISM:
Initially Penicillium notatum strain was used for fermentation of penicillin.
Then Penicillium chrysogenum was used.
The strain Penicillium chrysogenum gave a yield of 200 units/ ml. Further this
strain was improved by using strain improvement program and after strain
improvement the strain gave a yield of 761 units /ml by using submerged cultured
method.
The strain is maintained in dormant state by using lyophilization technique,
stored in liquid nitrogen in frozen state or in spore form.
10. INOCULUM PREPARATION:
Pure culture of Penicillium chrysogenum is prepared in adequate amount.
The primary stock is added in special agar, the special agar should
provide sporulation of spores and the sporulating medium is used to
prepare this working stock.
The sporulated spores are suspended in SLS solution in a proportion of
1:10,000 further this spores are added in a nutrient medium of wheat bran
plus nutrient and the flask are incubated for 5 to 7 days at 24 ° C.
This medium is used for heavy sporulation.
Now this spores are used as a innoculum in fermentation tank.
11. FERMENTATION PROCESS:
Fermentation of penicillin is carried out in trays or by submerged
culture method.
The 10 % of innoculum is added in the fermentor in aseptically.
The temperature of about 25 ° C to 26 ° C is maintained
. The sterile air supply is provided continuosly.
The fermentation is carried out for about 3 to 5 days.
During this fermentation process the samples are withdrawn
aseptically and checked for yield of penicillin, pH and
contamination.
It is monitored for foam formation also if foam is produced it is
controlled by antifoaming agent.
12. The pH of the fermentation media increases to 7.0 to 7.5 due to deamination
and release of ammonia.
Now at this point the micro-organism starts product synthesis by utilization
of lactose and production of penicillin.
Initially during 20 to 30 hours the fungal spores utilizes carbohydrates and
corn steep liquor and fungal spores develop as mycelium and further in the
duration of 48 to 96 hours the mycelium starts production of penicillin
product.
The yield obtained is 3 % to 5 % and 1500 unit per milliliter of fermentation
medium.
13. HARVEST AND RECOVERY:
Initially the mycelium and other solid suspended particles are removed by
filtration process.
Treated with solvent extraction procedure for separation of penicillin.
The penicillin is converted to anionic form by using phosphoric acid and
sulphuric acid.
Further the broth is extracted by using a organic solvent like methyl isobutyl
ketone or amyl acetate.
The extracted penicillin in solvent is back extracted in water by use of
potassium hydroxide and sodium hydroxide in form of salt.
The aqueous penicillin is acidified and re-extracted by methyl isobutyl ketone.
Thus extraced penicillin is then evaporated, crystallized and standardised.
14. STREPTOMYCIN:
Streptomycin is an bactericidal antibiotic drug belonging to the
class of aminoglycosides.
Used against TB.
Derived from actinobacterium Streptomyces griseus
Espescially used against gram negative bacteria
15. CHEMICAL STRUCTURE:
Chemically it contains 3
sugars derived from
glucose with C, O, N and H
elements.
Chemical formula :
C21H39N7O12
16. MEDIUM:
Carbon source: starch, dextrin, glucose, glycerol
Nitrogen source: natural agricultural by-products, soybean meal, corn steep liquor,
cotton seed flour, casein hydrolate, yeast. Inorganic N salts – ammoniumsulphate and
ammonium nitrate
Animal oil, vegetable oil and mineral oils.
Inoculum : S. griseus spores are maintained in soil stocks or lyophilizedin carrier are
inoculated into sporulation medium which bulds up mycelial inoculum.
18. FERMENTATION PROCESS:
Temperature :25 to 30 degree C
pH range : 7-8
Time : 5-7 days
High aeration and agitation
It involves 3 phases which are as follows..
19. PHASE 1
Initial fermentation phase – little production
Rapid growth with production of mycelial biomass
Proteolytic enzymatic activity releases NH3 from soyameal, raising the pH to
7.5
Characterized by the release of ammonia
Carbon nutrients of soya meal are utilized for growth
Glucose is slowly utilized with slight production of Streptomycin
20. PHASE 2
Little production of mycelia
Glucose added to the medium and ammonia released from
soya meal are consumed
pH remains fairly constant ranging between 7.6 - 8
21. PHASE 3
Final phase of fermentation
Depletion of carbohydrates from the medium
Streptomycin production ceases and bacterial cells begins to lyse
Ammonia from lysed cells increase the pH
22. RECOVERY AND PURIFICATION:
Mycelium is separated from broth byfilteration and streptomycin is
recovered
Broth is acidified, filtered and neutralized
Then it is subjected to column containing cation exchange resin to absorb
Streptomycin from the broth and column is washed with water and it is
eluted with HCl.
Dissolved in ethanol and filtered
Acetone is used to precipitate
Precipitate is washed with acetone and purified
23. USES
Treatment of diseases:
TB, Plaque
veterinary medicine against gram negative bacteria
Pesticides and fungicides
Cell culture
Protein purification