It is a new group of antibiotics obtained from
Substances of Rifamycin:
The isolated product has five active substances.
Rifamycin A,B,C,D and E.
Rifamycin B is the most active of all . It is
spontaneously transforms to more active
products like rifamycin O,S and SV. These are
In vivo Rifamycin SV shows good activity ,
tolerability and solubility properties and it
treats infection from gram positive bacteria
Stock Cultures of Nocardia mediterranea is
maintained insealed ampoules in lyophilized
Frozen vegetative mycelium of selected high
producing colonies in small vials at a low
temperature are highly stale over a long
period of storage.
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
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
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
The fermentation lasts for 300 hrs
Purification of Broth after harvest is done at
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