Rifamycin

1. Muneeba Ikram Roll no: 13009 Rifamycin

2. Introduction It is a new group of antibiotics obtained from Nocardia mediterranea S terptomyces sp Micromonospora locustis . Substances of Rifamycin : The isolated product has five active substances. Rifamycin A,B,C,D and E.

3. Rifamycin B is the most active of all . It is spontaneously transforms to more active products like rifamycin O,S and SV. These are microbiologically active . In vivo Rifamycin SV shows good activity , tolerability and solubility properties and it treats infection from gram positive bacteria

4. Inoculum Stock Cultures of Nocardia mediterranea is maintained insealed ampoules in lyophilized state. Frozen vegetative mycelium of selected high producing colonies in small vials at a low temperature are highly stale over a long period of storage.

5. Medium Vegetative Medium includes: Peanut meal (25g/l) Soyabean Meal (10g/l) Ammonium sulphate (10g/l) Propylene Glycol (5g/l) Glucose (110g/l) Fish Meal (20-40g/l)

6. Best yeild Best yield can be obtained when 5% inoculum of a preculture grown for 24 hours is used in aerated fermenters at 28 C It give a yeild of 6-7 g/l During fermentation N.mediterranea has high oxygen requirements in a definite period of growth production cycle. An air flow ranging from 0.8-1.5 l/min is essential.

7. Fermentation It is carried out in conventional bioreactors of 20-100 m3 volume. It is equiped with turbine , stirrers , baffles , air ring spargers and heating-cooling systems, In a fermenter. Consumption of glucose , growth of mycelium and production of antibiotic occur at the same time. At initial stages of growth , consumption of glucose and nitrogen is slow , however , it becomes very fast when mycelial growth starts.

8. Requirements The demand of oxygen is also very high at this stage . Metabolic activity of mycelium changes the initial pH 6.2-6.4 to 6.6-6.7 , later it decreases to 5.5-5.7 .pH again rises slowly until the end of fermentation and optimal pH 6.2-6.4 The fermentation lasts for 300 hrs

9. Purification and Recovery Purification of Broth after harvest is done at pH 7.5-8.0. The filterate is acidified (pH 2.0) Extraction of the product is carried with choloform , Re-extraction from chloroform is done in phosphate buffer of pH 8 followed by acidification of the aqueous solution and extraction with ethyl acetate from which it crystallizes