GB2073244A - A Process for Preparing Suspensions of Torula or Candida utilis - Google Patents

Abstract

Vinasse is used as the growth medium for torula or Candida utilis and ammonium and phosphorus salts are added. Molasses and Mg, Mn, Zn, B, Cu, Co, Mo, I and Se compounds can also be added. The suspensions can be used to produce animal feed supplements.

Description

1

GB 2 073 244 A 1

SPECIFICATION

A Process for Preparing Suspensions of Torula or Candida Utilis

The present invention relates to a process for producing suspensions of Torula or Candida utilis from vinasses.

5 Several processes for the obtention of Torula or Candida utilis are known. For instance, Yanson 5

and Bremer C. A. Vol. 51,11652, 1957, describe a method whereby Torula utilis is grown on malasses together with Saccharomyces at 28—30°C on laboratory scale. The yield was better in the case of the Torula, which was obtained within 9 to 12 hours due to a rise of the pH value from 4.4 to 8.2. at a pH value=7.8 the growth was blocked, as was demonstrated by the C02 produced.

10 A further process is described by Tsugio Matsuo C. A. Vol. 63, 170893,1965, in which process 10

the culture is effected on cane molasses.

However, none of the known processes proposes to grow the Torula in vinasse with the addition of oligoelements independently.

Thus the invention provides a process for preparing suspensions of Torula or Candida utilis which 15 comprises growing Torula or Candida utilis in vinasse in the presence of ammonium and phosphorus •)5 salts.

The process of the instant invention proposes the development of Torula or Candida utilis strains to which nutritious salts are added either in a discontinuous or continuous system, and it achieves a yield not reached heretofore by the known processes.

20 The continuous process is of high yield and low cost. The yield achieved by the process of the 20

invention amounts up to 6.0 g/l. h, whilst the known processes only yield 0.99 to 3.0 g/l. h.

For the purpose of achieving such high yield, the vinasse medium is modified with: 1) a variable amount of molasses (e.g. 0—2%) depending on the organic matter content of the raw materials susceptible of assimilation; and/or 2) one or more compound of one or more elements such as Mg, Mn, 25 Zn, B, Cu, Co, Mo, I and Se. This solution is independently added during the continuous process, that is, 25 the oligoelements are not incorporated in the medium but directly or independently added to the manufacture vessel.

For the saka of high yield, bacterial and fungical contaminations should be avoided. Bacterial contamination can be controlled by: a) adding chloramphenicol and formol; b) working at a pH value 3 30 by the addition of H2S04. Fungical contaminations can be avoided by working at high dilution-speed 30 rates, such as 0.30 to 0.40.

The dilution speed D results from the following equation:

F= flow rate of feed (litres/hour)

D=—

y — operating volume (litres)

The Torula utilis strain corresponds to Mayor Var. NRRL 1084.

35 Example of the Preparation of Torula:

To 1000 litresof distillery vinasse 2 Kg of ammonium sulphate and 0.2 Kg of ammonium phosphate or superphosphate are added and placed in a fermentor provided with stirring and enough aeration for the development of an aerobe microbian process. The fermentation medium is inoculated with a Candida or Torula utilis suspension obtained in a 5 litres laboratory fermentor equipment 40 containing a vinasse medium. The fermentation process is effected at a controlled 30°C temperature,

with aeration and adequate stirring being maintained during the entire growth in order to obtain a concentration of 12 to 30 g/l of Torula dry matter within a period of time ranging from 20 to 24 hours.

It will also be possible to carry out the production process in a continuous system, thereby achieving a high yield. In this case the following way of processing will be followed: it will be started 45 with a discontinuous step up to a dry matter concentration of 12 to 15 g/l and thereafter the medium of vinasse and the already mentioned salts will be fed, which medium may also include molasses in variable concentrations of 0 to 2% depending on the organic matter contents susceptible of assimilation in the vinasse. During the entire development of the process a oligoelement solution having the following composition: manganese chloride: 1.4 g; boric acid: 1.53 g; zinc sulphate: 0.90 g; 50 copper sulphate: 0.40 g; cobaltous chloride: 0.02 g; sodium molybdate: 0.05 g; potassium iodide:

0.0013 g can be added separately; for 201 of hydrochloric acid-acidulated water at a concentration sufficient to maintain all components in solution. The above saline solution may also contain sodium selenite in a variable proportion from 0.02 to 0.3 ppm in relation to the final medium. A 20 litres oligoelement solution will be employed for a 1000 litres vinasses medium.

55 The bacterial control will be either effected by the addition of chloramphenicol (0.7 mg/l) and formol (0.006%) or by the addition of sulfuric acid to the culture medium until a pH value of 3 or less is achieved. The filamentary-fungus contamination will be controlled by maintaining the feeding of the medium at D rates of 0.30 to 0.40.

Working under the above conditions 2700 to 3600 litres per hour of vinasse in a fermentation

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40

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2

GB 2 073 244 A 2

vessel containing 9000 useful litres of culture medium may be processed. The yield achieved under these conditions amounts to 4.5 to 6.0 g/litre . hour of dry matter, which means that for said vessel volume a yield of 972 to 1296 Kg per day of dry Torula can be obtained.

The Torula obtained was subjected to analysis (on dry basis), the results of which were as 5 follows: 5

%

Proteins (N2x6.25)

46.20

Fibre

3.17

Fats

1.03

Ashes

11.26

Calcium

1.42

Phosphorus

1.44

Group B vitamins present

The Group B vitamins, analysed and expressed in mg/Kg of dry levure, are as follows:

Riboflavin

44

15

Pyridoxine

29

Choline hydrochloride

4000

Folic acid

23

Niacin

500

Calcium pantothenate

83

20

Biotin

1.1

As regards proteins, the essential aminoacid contents being expressed in g/16 g N, the following results were obtained:

Phenyl alanine

5.25

Leucine

8.75

Isoleucine

5.42

Methionine

1.75

Cysteine

0.37

Valine

6.42

Threonine

5.55

Lysine

8.42

Tryptophan

1.30

The suspensions of Torula or Candida utilis have protein contents which enable their use as starting materials for producing animal feed supplements, e.g. as described in our copending British 35 Patent Application of ever date (agents ref. 42.134—671). 35

Claims (8)

Claims

1. A process for preparing suspensions of Torula or Candida utilis which comprises growing!

Toruia or Candida utilis in vinasse in the presence of ammonium and phosphorus salts.

2. A process as claimed in Claim 1 wherein one or more compound of one or more of the

40 elements Mg, Mn, Zn, B, Cu, Co, Mo, I and Se is also added to the fermentation medium. 40

3. A process as claimed in Claim 2 which is operated continuously and said compound or compounds are added to the fermentation medium in the form of a solution.

4. A process as claimed in any one of the preceding claims wherein molasses is also added to the fermentation medium.

45

5. A process as claimed in any one of the preceding claims wherein chloramphenicol and formol 45 are also added to the medium.

6. A process as claimed in any one of the preceding claims wherein sulfuric acid is added to maintain a pH of 3 or less.

7. A process as claimed in Claim 1 and substantially as described herein in the Example.

50

8. A suspension when prepared by a method as claimed in any one of the preceding claims. 50

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1981. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1 AY, from which copies may be obtained.