PROCEDE D'ISOLATION DE LA SALINOMYCINE A PARTIR D'UN BOUILLON DE FERMENTATION

A METHOD FOR ISOLATING SALINOMYCIN FROM FERMENTATION BROTH

Abrégé français

L'invention concerne un procédé servant à isoler la salinomycine dans le but d'obtenir un produit granulé. Le but susmentionné est atteint au moyen d'un procédé d'isolation de la salinomycine à partir du bouillon de fermentation, lequel procédé consiste à ajuster le bouillon de fermentation de salinomycine à une plage de pH acide. Une aide à la filtration inerte, telle que de la terre de diatomées, des zéolites, de la farine de bois ou un mélange de ces dernières est ajouté dans une quantité de 5 à 20 % en poids, en fonction du poids du bouillon de fermentation. La biomasse est séparée par filtration, granulée et séchée dans séchoir à lit fluidisé. Les granulés secs sont moulus et tamisés jusqu'à une taille de particule requise.

Abrégé anglais

The present solution refers to a method of isolating salinomycin for the
purpose of obtaining a granulated product. The purpose aforementioned is
reached by a method for isolating salinomycin from the fermentation broth
according to the invention, the nature of which consists in that the
fermentation broth of salinomycin is adjusted to an acidic pH range. A
suitable inert filtration aid such as diatomaceous earth, zeolites, wood flour
or a mixture thereof is added in an amount of 5 to 20 wt % referred to the
weight of the fermentation broth. The biomass is separated by filtration,
granulated and dried in a fluid bed drier. The dry granules are ground and
sieved to a required particle size.

Revendications

5
CLAIMS
A method for isolating salinomycin from a fermentation broth, characterised in
that the fermentation broth is adjusted to an acidic pH value of 4 to 5, a
suitable
inert filtering aids, such as diatomaceous earth, zeolites, wood flour or
mixtures
thereof (5 to 20 wt % referred to the weight of the fermentation broth) are
added
to fermentation broth, the biomass is separated by filtration, granulated and
then dried in a fluid bed drier, and the obtained dry granules are ground and
sieved to a required particle size.

Description

CA 02407708 2002-10-29
WO 01/83801 PCT/SKO1/00015
A METHOD FOR ISOLATING SALINOMYCIN FROM FERMENTATION BROTH
Technical field
The invention relates to a process of isolation of salinomycin from the
harvested fermentation broth.
Present Technical Status
Spray drying of the fermentation broth to which an anti-caking agent and a
filling
agent have been admixed, is used for preparation of salinomycin feed grade or
the pure form is isolated after the biomass separation by extraction,
concentration
and purification of the raw product by recrystallization. Isolation of the
pure form is
rather demanding as concerns the high production costs and mechanical-
technological equipment of the operation plant (US pat. Document 4,212,492, US
pat. Document 4, 137, 247).
There is no need for pure form preparation should salinomycin be used as a
veterinary drug or growth stimulator. After completion of the fermentation,
the
treated broth can be directly dried together with anti-caking agents admixed
to it.
Before drying, the broth can be concentrated on an evaporator (US pat.
Document 4,395,491). .
The harvested fermentation broth of salinomycin contains many by-products
that pose a problem after spray drying of the broth. Solid substances
agglomerate, form clods and can not be further processed. The major reason
for the agglomerate formation is the content of fat. The fats contained in the
solids manifest themselves predominantly in high temperature processing, when
they are moist and at mechanical stress. The product obtained from the spray
drier is very dusty, and therefore, it is necessary to granulate it (US pat.
Document 5,529,9'11).
The granulation process can be performed either directly in a combined fluid
bed- spray drier, or at a subsequent isolation step using a dry or wet method
of
processing.
It has been found out that ifi is possible to isolate the solid substances in
the form
of granules. from the salinomycirt fermentation broth without the formation of
agglomerates. .

CA 02407708 2002-10-29
WO 01/83801 PCT/SKO1/00015
Backgiround of the Invention
The above disadvantages are eliminated by the method for isolating salinomycin
from the fermentation broth according to this invention. The nature of the
invention
consists in that the salinomycin fermentation broth is adjusted to an acidic
pH
value of 4 to 5. A suitable inert filtration aid such as diatomaceous earth,
zeolites, wood flour or a mixture thereof is added in amount ranging from 5 to
20
wt % referred to the weight of the treated fermentation broth. The biomass is
separated by filtration then granulated and dried in a fluid bed dryer.
Subsequently, the granules are ground and sieved to the required particle
size.
The present method ensures a product which satisfies the veterinary code. It
is
advantageous that the active substance exists within an acidic pH range in
cells of
the biomass, and thus it is possible to discard the separated filtrate
obtained
by this process to the biological waste water treatment plant for aerobic
treatment. Further, the dry matter content of the biomass thus obtained is
higher than that of the fermentation broth, it being the reason that power
consumption needed for drying the biomass is lower than the consumption for
drying the whole amount of the fermentation broth.
Examples of Embodiments of the Invention
Example 1
The fermentation broth obtained by fermentation of Streptomyces albus had,
after 128 hours of cultivation, the pH value of 6,1 and a salinomycin content
of
18,4 g/kg. 527 kg of the harvested fermentation broth have been adjusted by an
addition of 10% HCI to a pH value of 4,0. Wood flour (8 wt % referred to the
weight of the broth) was added to the treated fermentation broth. Using a
rotary
vacuum filter filled with wood flour we obtained 119,7 kg of biomass and 460,7
kg
of filtrate which contained less than 0,01 % of salinomycin and after
neutralisation
it was discharged to the waste water aerobic treatment plant.
The separated biomass passed through a granulator and was dried in a fluid
bed drier giving an amount of 74,2 kg of the product containing 12,3% of
salinomycin.

CA 02407708 2002-10-29
WO 01/83801 PCT/SKO1/00015
3
Example 2
The fermentation by Streptomyces albus of the fermentation broth was
terminated after 120 hours. The broth had a pH value of 6,0 and a
salinomycin content of 22,6 g/kg. An amount of 589 kg of fermentation broth
was adjusted by addition of 10% HCI to a pH value of 5,0. Zeolite and
diatomaceous earth were added (15 wt % referred to the weight of treated
fermentation broth). Using a rotary vacuum filter filled with diatomaceous
earth,
we obtained an amount of 184,7 kg of biomass and 495,6 kg of filtrate which
contained less than 0,02% of salinomycin and was discarded as in Example 1.
The separated biomass was granulated and dried in the fluid bed drier giving
an
amount of 106,5 kg product containing 12,1% salinomycin.
Example 3
The fermentation broth obtained by fermentation of Streptomyces albus had,
after 124 hours of fermentation, a pH value of 6,2 and a salinomycin content
of 17,1 g/kg. By addition of a NaOH solution, a pH value of 7 to 8 was
reached.
The fermentation broth thus treated was heated to a temperature of 60
°C, and
after cooling, the pH value was adjusted by diluted HCI as in Example 1.
Zeolite
(20 wt % referred to the weight of the fermentation broth) was added to 524 kg
of
the treated fermentation broth. We filtered the mixture through a layer of
diatomaceous earth filter aid using a rotary vacuum filter and obtained an
amount
of 184,7 kg of biomass and 495,6 kg of filtrate which contained less than
0,001
of salinomycin. The filtrate was discarded as in Example 1.
The separated biomass, having passed through a granulator, was dried in a
fluid bed drier giving an amount of 80,7 kg of the product containing 10,9% of
salinomycin.
Example 4
The fermentation broth obtained by fermenting Streptomyces albus had, after
128 hours of fermentation, a pH value of 6,3 and a salinomycin content of
15,5 g/kg. An amount of 566,6 kg of the fermentation broth was adjusted by an

CA 02407708 2002-10-29
WO 01/83801 PCT/SKO1/00015
4
addition of 10% HCI to a pH value of 4,7. Diatomaceous earth (5 wt % referred
to
the weight of the fermentation broth) was added to the treated fermentation
broth.
We used a rotary vacuum filter filled with diatomaceous earth. We obtained
100,7 of kg biomass and 500,6 kg of filtrate with a low content of salinomycin
which, following neutralisation, was discarded fio the waste water aerobic
treatment plant. The separated biomass was then processed by granulation,
dried in the fluid bed drier giving an amount of 68,4 kg of a dry product
containing
12,8% of salinomycin.
Industrial Applicability
Salinomycin is used in veterinary medicine as a coccidiostat coccidium and as
a growth stimulator in feeding farm animals