LU86584A1 - PROCESS FOR THE PREPARATION OF LACTIC ACID BY FERMENTATION OF WHEY - Google Patents

Description

‘- ν'- L-3140

* Γ Ô C K Q / »GRAND-DUCHY OF LUXEMBOURG

Patent Np 0 0 0 0 “. .

I Minister I of September 15, 1986 jBfeggt of the Economy and the Middle Classes! , 15¾¾ Intellectual Property Service

1_I_ LUXEMBOURG

3.¾

Patent Application: * ----------------------— ..— ^ --------------- ---------------------------: - (1) I. Request SYHFINA-OLEOFINA SA, Zone ...... Industrielle D , B-6538 Manage, (2) represented by Mr. Jean Waxweiler. 21-25 Allée S chef fer, Luxembourg, acting as agent_ ------------------------------- (3) deposit ) this fifteenth, september one thousand nine hundred eighty-six-six (4) to -, jr.5jL.0QL. hours, at the Ministry of Economy and Average Qasses, in Luxembourg: 1. the present request for the obtaining of a patent of invention concerning:

Er-OGédë-de- prëpaEation -d -'-- lactic-acid-by-fermentation ______ (5) of, JLactos erum__________________________ 2. the description in language - ^ raa9aLSe _____of the invention in triplicate; 3. ---- 1 --------------- drawing boards, in triplicate; 4. the receipt of the taxes paid to the Luxembourg Registration Office, on 15.09.1986 ____________; 5. the delegation of power, dated ___Manage__ on September 8, 1986; 6. the successor document (authorization); 1 declares (s) assuming responsibility for this declaration, that the inventor (s) is (are): (6) \ Marcel ...... HOEMÄN ---------- --------------------------------------_--- f Bond sberg.fin._2 _____________________________________________________________________________ ü B-1981 Tervuren-Vossem! .................................................. .............. “................................... ........... ..................

! ------- ------------------------------------------- ---------------------------------------------------------- ---------------------------------------------------------- - ~ \ ......................... = _________________________________________________________________________________________________________________________________________________ I claim (s) for the above patent application the priority of one (s) request (s) from (7) .......................................... ......... L ........................................ ................................... filed in (8) ____ L ...... ...............................

on (9) ....................... L ...........-.......... ......................................._.......... ..............__................................... ....................................: ............. .........

under N ° (10) - / _ ___________________________________________________________________________________________________ in the name of (11) _________ / .______________________________________________________________________________ elect (elect) domicile for him / her and, if designated, for his / her representative, in Luxembourg ........ .....

-21 = 2-5 .....- Allee ...... SGbe-ff-er-T-Luxembourg ---------------------- ----- (12) requested) the issue of a patent for the subject described and represented in the abovementioned appendices, 'with postponement of this issue to ____ 1.8 _____________________________ y,] ______________ months. (13)

The depositor / agent: Jean Waxweiler ____ .. (14): - Π. Deposit Minutes

The above application for a patent for invention has been filed with the Ministry of the Economy and the Middle Classes, i Department of Property InteHpf1TISÏÏS "in" imxembourg, dated: 15.09.1986 I / i Pr. The Minister of Savings and Average Qasses,! At .1JL / J-LQ _______ hours / = / d pd

i l · \ 4? / The head of the intellectual property service, i 7x Γ ‘. A 68007_NJ * / "/ V_ I EXPLANATIONS RELATIVE Atî FORMUlSBLC DE gfjÔT ~" 'L-3140! /

DESCRIPTIVE MEMORY FILED IN SUPPORT OF A PATENT INVENTION APPLICATION IN THE GRAND DUCHY OF LUXEMBOURG

SYNFINA-OLEOFINA S.A.

Zone Industrielle D B-6538 Manage

Process for the preparation of lactic acid by fermentation of whey.

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PROCESS FOR THE PREPARATION OF LACTIC ACID BY FERMENTATION OF WHEY

The present invention relates to a process for preparing lactic acid by fermentation of whey, in the presence of lactic acid bacteria. In particular, the present invention relates to a process for continuously preparing lactic acid, as well as an apparatus for carrying out this process. More particularly still, the process of the present invention relates to a production of lactic acid by extractive fermentation of whey.

We know that whey is a low-value by-product from the processing of milk to produce high value-added products such as cheese. It is therefore interesting to be able to develop the whey in particular to lead to the formation of other products by fermentation.

Methane, ethanol and yeasts for food use have already been obtained from whey taken as fermentation substrate. However, the most interesting product to prepare is lactic acid.

This is obtained by fermentation of the lactose contained in the whey.

However, the lactose fermentation processes have numerous drawbacks, in particular due to the necessary addition of neutralizer to the medium, which is unfavorable for the development of a continuous process, and especially for the purification operations which result from the Λ - 2 - presence of lactate.

Thus, in traditional processes, whey, molasses, etc. are used as the fermentation substrate, supplemented with suitable products to obtain a suitable protein and vitamin content. The strains used for fermentation are of the genus Lactobacillus and of one of the groups chosen from Thermobacterium and Streptobacterium. The fermentation is carried out in the presence of neutralizer, in this case calcium carbonate, which neutralizes the lactic acid formed by fermentation as it is formed. When the starting species is exhausted, it is brought to a boil and filtered. The filtrate contains only 10% crude lactic acid, which must be purified to be usable. This process leads to a significant loss in starting material, but above all to a low yield.

In order to overcome certain drawbacks, it has already been proposed to use other strains, such as Lactobaci11 us LBR, at high speed of lactic acid production, or even by trying to remove lactic acid from the medium as and when measure of its production.

Recently, it has also been proposed to purify the ·., Product resulting from ultrafiltration by elec tr odia 1 ys e, ma is once again, this type of process does not give significantly higher yields, but moreover does may be difficult to carry out continuously since there is always the addition of neutralizer to the fermentation medium.

The subject of the present invention is a new process for producing lactic acid by fermentation from whey, this process not requiring the addition of any neutralizer to the fermentation medium.

The present invention also relates to a process for producing lactic acid by fermentation, making it possible to obtain a clearly lactic acid yield.

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The present invention also relates to a process for producing lactic acid by fermentation, which makes it possible to avoid the numerous purification operations provided for in the prior processes.

The present invention also relates to a process for producing lactic acid by fermentation which can be easily carried out continuously, without the risk of blocking the fermentation reactor.

The process of the present invention for producing lactic acid by fermentation is characterized in that it comprises the following stages: - a whey permeate containing 30 to 70 g of lactose / 1 is introduced into a buffer tank; - the whey is pumped in a fermenter equipped with a stirring system and thermostatically controlled at a precise temperature between 28 and 45 ° C; - Introducing into the fermenter bacteria of the Lactobacillus type at high acidification speed as well as biofactors; - the fermentation must is subjected to ultrafiltration; - the retentate is returned to the fermenter; . " - the filtrate is pumped through a system of ion exchange columns comprising at least one anion exchange column, · - the lactic acid is recovered by frontal elution with a solution of a strong mineral acid.

According to the process of the invention, whey is deproteinized, or as such, is introduced into a fermenter. The whey can thus be used without having to undergo a prior decationization.

Fermentation is then generally carried out in the presence of lactic acid bacteria, · when this type of bacteria is used, lactobaci11 es thermophi1 es are used at high speed of acidification. It should be noted that in the process of the invention, the addition of neutralizer is not required for pH control, which is a definite advantage.

Fermentation is carried out under culture conditions such that the propagation of other microorganisms is strongly curbed. Typical operating conditions are as follows.

The fermentation temperature is chosen between 28 and 45 ° C. The fermenter is equipped with a thermostat system to maintain the defined fermentation temperature.

The quantity of sugar regulates the feed to the fermenter, and it is stabilized in the effluents at approximately 3 to 5 g / 1 of effluent.

As suitable biofactors which are added to the fermentation medium, mention may in particular be made of yeast extracts, bactopeptones, or protein hydrolysates such as fish lysates. In order to facilitate the introduction of these biofactors into the medium, it is often desirable to add a solubilizing agent, such as for example sodium acetate, or another suitable agent.

At the same time as the biofactors, a tracer can also be added to the medium.

The fermentation must obtained in the previous step is subjected to an ultrafiltration step which makes it possible to recover on the one hand a retentate containing mainly whole cells as well as products of cell lysis, and on the other hand 1 1 trafi1 trat containing lactic acid. The retentate is at least partially recycled to the fermenter, while the ul trafi11rat is sent for treatment in the ion exchange columns.

The processing system of the ultrafiltrate can be a single column; in this case, it is filled with an anion exchange resin, used in hydroxyl form.

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This resin captures the lactic acid from fermentation, and the effluent from the column is partially recycled in the fermenter so as to regulate the pH of the latter. When the column is saturated, the effluent from the ultrafiltration is introduced into another column, while the first is regenerated by frontal elution with a current of a strong acid, at least stronger than lactic acid, until complete recovery of lactic acid. This column is then regenerated with ammonia so as to be in its initial hydroxyl form.

According to a preferred embodiment of the process of the invention, a treatment system with two ion exchange columns is used. The ultrafiltration effluent is sent to a first column filled with an anion exchange resin, used in hydroxyl form, where the anions, including the lactate ions, are fixed. As the strong acid anions are preferably fixed on this first column, the latter is saturated with such ions and the lactate ions are displaced and fixed on a second column of the same type. The effluent from this last column is partially recycled to the fermenter for the same reasons as above. This embodiment has the advantage of making it possible, by adjusting the operating conditions, to obtain a second column on which there are practically only lactate anions.

According to a more preferred embodiment, a third column of the same type is placed downstream of the second column, which allows the second column to be saturated while fixing all of the lactate ions.

According to one embodiment of the invention, the resin present in the second column is also used in its hydroxyl form, but it goes without saying that other counterions can be used, such as, for example, the acetate ions.

When this second column is saturated, the 'v / Γ - 6 - lactate ion fixed in it is released in the form of lactic acid by frontal elution with a current of a solution of a strong acid, at least more stronger than lactic acid, until complete recovery of lactic acid.

The two columns are then regenerated with ammonia, or, as the case may be, with another compound such as an acetate, so as to be in their initial form.

According to a preferred embodiment of the process of the invention, the effluent from the ultrafiltration is first passed over a cation exchange column, which has the effect of eliminating the cations of the influent from the exchange exchangers. ions and thus promote the subsequent fixation of lactic acid.

It is obvious that these different columns must operate alternately with others so as to be able to ensure the continuous operation of the operation.

It is desirable to carry out the recovery of lactic acid by frontal elution with an ascending current of a solution, denser than that of lactic acid, of a non-oxidizing mineral acid stronger than lactic acid.

By way of example of such an acid, mention may in particular be made of sulfuric acid. It is understood that the lactic acid could be displaced by a downdraft of a solution of a strong acid, but less dense than that of lactic acid, for example an HCl solution.

The process of the invention is also described with the aid of the appended drawing in which the Figure represents a complete diagram of the process of the invention.

Referring to the Figure, the whey located in the buffer tank 1 is continuously pumped through line 2 in the fermenter 4 equipped with a heating system and an agitator (5).

The biofactors, optionally the solubilizing agent, and if desired the tracer, contained in the reservoir 6, are added to it via the pipe 7.

The fermentation wort is sent continuously through line 8 into the ultrafiltration device 9. The retentate from the ultrafiltration is recycled through line 10 into the fermenter while the ultrafiltrate is sent through line 11 into the ion exchange column device 20. A two-column system is shown.

The ultrafiltrate is sent to the first column 21 which is filled with an anion exchange resin, used in its hydroxyl form. This first column becomes saturated with strong acid anions, while the lactate ions, which are attached to it at the start, are gradually displaced and will become fixed in the second column 22 which also contains an anion exchange resin used under its hydroxyl form.

During operation, the effluent from this column 22 is partially recycled to the fermenter via line 23 in order to regulate the pH of the latter. When the column 22 is saturated with lactate ions, it is first washed with water to remove the fermentation effluent which is in the column, then an upward flow of a solution of strong acid which, by frontal elution, displaces the lactate ions in the form of lactic acid. When this operation is complete, the columns 21 and 22 are regenerated so that they are found in their initial form.

The following examples are given in order to better illustrate the process of the present invention but without however limiting its scope.

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Example 1

Continuous fermentation was carried out for 10 days.

A 20 L fermenter equipped with a pH probe, a temperature control system, and a level control system was fed with a solution of whey permeate at 70 g lactose / 1.

75 g of yeast extract, 37 g of sodium acetate (used as solubilizing agent) and 0.4 g of MnSO 4 (used as tracer) were added thereto per 15 l of permeate. The temperature in the fermenter was 40 ° C.

The average residence time in the fermenter was between 25 and 40 hours. The optical density stabilized at around 30. The fermentation must was drawn off at the rate of 0.2 to 0.6 1 / min. and we sent it to the ultrafiltration.

The ion exchange column system was supplied with liquid from the ultrafiltration step, at a flow rate of 0.17 to 0.32 l / min.

The system used is a 2-column system operating alternately. These are 3 1 columns filled with 2 1 of Duolite A 374 resin. The medium leaving the column in operation is recycled to the fermenter.

When the column is saturated with lactic acid, sulfuric acid is introduced into the column against the current, from bottom to top, and at a flow rate of 30 ml / min., So as to displace the lactic acid and to retrieve it.

In the test which was carried out, the fraction passing between pH 1.6 and pH 1 is recovered and 600 ml of 16% lactic acid are obtained per liter of resin.

Example 2

A batch fermentation was carried out for 48 hours in the fermenter described in Example 1. The volume

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The medium was 15 l of a solution of whey permeate containing 70 g / l of lactose. The temperature was 40 ° C.

After 23 hours, 75 g of bactopeptones, 37 g of Na acetate and 0.37 g of Μ n S 0 ^ were added.

The fermentation wort was subjected to ultrafiltration and the ultralight was pumped through the ion exchange column system described in Example 1.

The column was saturated after 18 hours of passage of the ultrafiltrate, at a flow rate of 12 l / hr.

Sulfuric acid was thus introduced against the current and from bottom to top and at a flow rate of 30 ml / min so as to displace the lactic acid.

In the test carried out, the fraction passing between pH 1.6 and pH 1 is recovered and 560 ml of 32% lactic acid are obtained per liter of resin.

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Claims (8)

1. Method for producing lactic acid by fermentation, characterized in that it comprises the stages which consist in: introducing into a buffer tank a whey permeate containing 30 to 70 g of lactose per liter, · pumping the whey into a fermenter provided with a stirring system and thermostatically controlled at a precise temperature of between 28 and 45 ° C., - introducing into the fermenter bacteria of the lactobaci11 us type at high acidification speed as well as biofactors; subject the fermentation must to ultrafiltration; return the retentate to the fermenter; pumping the filtrate into an ion exchange column system comprising at least one anion exchange column; recover the lactic acid by frontal elution with a solution of a strong mineral acid. 2. Method for producing lactic acid according to claim 1, characterized in that the ultrafiltration filtrate is pumped through a system of exchange columns. ” ions comprising at least two columns, and preferably three or four columns. 3. A lactic acid fermentation process according to claim 2, characterized in that the ion exchange column system comprises at least a first column for the pretreatment and a second anion exchange column. 4. A lactic acid fermentation process according to claim 3, characterized in that the ion exchange column system comprises, for the pretreatment, a 'cation exchange column, followed by an exchange column | / m - 11 - Anions to retain the anions preferentially attached to lactate. 5. Method for producing lactic acid according to claim 3, characterized in that the ion exchange column system comprises, for fixing the lactate ions, two anion exchange columns in series. 6. A method of producing lactic acid according to any one of claims 1 to 5, characterized in that one uses as biofactors yeast extracts, bactopeptones and / or protein hydrolysates such as fish lysates. 7. A method of producing lactic acid according to any one of claims 1 to 6, characterized in that one carries out the recovery of lactic acid by frontal elution with a mineral acid which is stronger than the acid lactic acid, in a denser solution than that of lactic acid. 8. A method of producing lactic acid according to claim 7, characterized in that sulfuric acid is used to recover the lactic acid by frontal elution. {Wuilj