JPH0638760B2 - Method for producing sugar-dense product for fermentation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a molasses product for fermentation used as a fermentation raw material. More specifically, molasses is treated with an electrodialysis device that combines a neutral membrane and a cation exchange membrane to remove fermentation inhibitors such as cations and anions contained in molasses and then ferment the molasses. It relates to the use of molasses used as a raw material.

Molasses is generally used in the largest amount as a fermentation raw material. However, much knowledge has been obtained from the past regarding the fact that fermentation inhibitory substances in molasses cause the decrease in fermentation productivity. Therefore, it has been practiced to use molasses as a raw material for fermentation after treating it with various methods, but an appropriate method has not been invented in terms of yield and cost. Therefore, it has been desired that the molasses treated by a method different from the conventional method is used as a fermentation raw material to improve the fermentation productivity and reduce troubles during the purification of the fermentation product.

The inventors of the present invention have already referred to a desalting and refining method of a sugar solution by electrodialysis using a polyvinyl alcohol-based diaphragm (Patent No. 835862, Japanese Patent Publication No. 51-9016) and "Sugar solution". Purification method "(Patent No. 1014134,
The invention of Japanese Examined Patent Publication No. 54-31050) has been completed, but the present invention has now been completed as one field of application. That is, the present inventors electrodialyze raw molasses by using an electrodialyzer having a multi-chamber structure in which a plurality of cation exchange membranes and neutral membranes are alternately combined, and cations such as K, Ca, Na, and Mg. After removing the anions such as Cl, SO _{4 and the} like from the molasses to reduce the total ash content in the raw molasses to within the range of about 1/2 to about 1/4, the molasses is mainly used as a carbon source for alcohol. When fermentation and amino fermentation are carried out, the present invention has been completed by finding advantages such as improvement of fermentation productivity, ease of operation during purification of fermentation products, and reduction of scale during heating.

It has been reported in many reports that when the concentration of salts contained in molasses is high, it has a fermentation inhibitory effect.However, if the salt is removed from molasses and then used as a fermentation raw material, it is industrially costly. It wasn't profitable. For example, the adoption of electrodialysis or the like using a cation and anion exchange resin or a cation and anion exchange membrane has drawbacks, especially economical disadvantages, and practical application of molasses for use as a fermentation raw material is not possible. It was difficult.

By electrodialysis using a neutral membrane and a cation exchange membrane used by the present inventors, 70% or more of ash content in Oki fly molasses was removed, and in ethanol fermentation using the molasses mainly as a carbon source, The fermentation yield increased to more than 60% as compared with the untreated molasses. In addition, in the case of L-lysine fermentation, which is a typical example of amino acid fermentation using molasses as a fermentation raw material, in both cases of molasses produced from Oki fly and molasses produced from filipin, the final L- The productivity increased to lysine concentrations of over 50% and over 60%, respectively. As described above, the fermentation productivity could be improved by mainly using the molasses treated by electrodialysis using the neutral membrane and the cation exchange membrane as the carbon source. Furthermore, since many cations and anions are removed from the treated molasses, when molasses was charged at the same total sugar concentration, treated molasses was used as compared to the untreated molasses, as is generally done. The lower the ash content, the lower the brixiness. Consequently, the viscosity, specific gravity, osmotic pressure, etc. of the culture broth are reduced, facilitating the operation during fermentation and refining the fermentation products, and finding the advantage that scale generation during heating such as sterilization due to ash content is reduced. It was done.

Example 1 An example in which molasses obtained by electrodialyzing raw molasses produced in Oki fly was used as a raw material for ethanol fermentation is shown below.

Preparation of treated molasses Molasses 8.0 produced in Okibae adjusted to Brix 50 is an effective membrane area of 0.775 dm ² neutral membrane (product of Taito Corporation, trade name: Taito N-4 membrane) and cation exchange membrane (Asahi Kasei). Co., Ltd., trade name: Aciplex CK-1) and 2 alternately
It was treated batchwise with an electrodialyzer set on a support frame at intervals of 0.75 mm, 0 sheet each. Operating conditions are cell voltage 2.0V, average current density 43Amp / dm ² , flow rate 70 / h
r, electrodialysis time is 6 hours. The molasses after electrodialysis was concentrated to obtain treated molasses.

Table 1 shows the analytical values of the molasses produced by Oki fly and the molasses before treatment. However, percentages and ppm are shown on a weight basis.

Fermentation test The strain used is Saccharomyces cerevisiae.
cerevisiae) Association No. 7 64C (provided by the Brewing Society). The medium used is as follows.

Preserved slant (1% yeast extract, 2% polypeptone (product of Wako Pure Chemical Industries, Ltd.), 1.5% agar), preculture medium (1% yeast extract, 2% polypeptone, 5 glucose)
%), And the main culture medium [molasses (28% total sugar, that is, molasses containing 28% as total sugar in this medium), ammonium sulfate 2
%].

For pre-culturing, 250 ml of pre-culture medium was put into a 500-ml Erlenmeyer flask, and after sterilization, 1 platinum loop was inoculated from the preserved slant and cultured at 30 ° C. for 20 hours on a rotary shaker (rotary shaker). For the main culture, 4.5 volumes of the main culture medium was charged into a 10-volume bottle incubator (Jahuamenta), 50 ml of the preculture medium was inoculated, and the cells were cultured at 30 ° C. and 200 ppm for 6 days. Fermentation test is (a) treated molasses only; (b) mixed molasses containing 9 parts treated molasses and 1 part untreated molasses; (c) 8 parts treated molasses and 2 molasses before treatment
The above-mentioned four types of molasses were used.

The results of the fermentation test are collectively shown in Table 2.

Example 2 L molasses obtained by electrodialyzing raw molasses produced in Oki fly
-The example used as a raw material of lysine fermentation is shown below.

Preparation of Treated Molasses Molasses 9.5 produced in Okibae adjusted to Brix 50 was treated with the same dialyzer as that used in Example 1. Operating conditions are cell voltage 2.0V, average current density 4.39Amp / dm ² ,
The flow rate is 70 / hr and the electrodialysis time is 7 hours. After electrodialysis, it was concentrated to give treated molasses.

Table 3 collectively shows the analytical values of the molasses produced by Oki fly and the molasses before treatment.

Fermentation test The strain used is Corynebacterium glutamicum (Coryne
bacterium glutamicum) ATCC 13280. The medium used is as follows. Preserved slant (meat extract 10g,
Polypeptone 10 g, NaCl 5 g, agar 1.5%, pH 7.
0), pre-culture medium (glucose 20 g, yeast extract 1
g ,, NZ-Amine (Wako Pure Chemical Industries, Ltd. product brand name) 6
g, ₄ g of NH ₄ Cl, 5 g of KH ₂ PO ₄ , 1 of Na ₂ HPO ₄ · 12H ₂ O
5g, MgSO ₄ · 7H ₂ O of 0.25g, FeSO ₄ · 7H ₂ O 0.0
1 g, 0.01 g of MnSO ₄ .4H ₂ O, deionized water 1, pH
7.0) Main culture medium [molasses 50 g total sugar (total sugar 50 g
Containing molasses), NZ-Amine 15 g, NH ₄ Cl 10 g,
Adjusted to 1 with deionized water), and supplemented medium (molasses 500)
g total sugar, 150 g of NH ₄ Cl, adjusted to 1.5 with deionized water). For pre-culture, pre-culture medium 10 in 500 ml Sakaguchi flask
After injecting 0 ml and sterilizing, inoculate 1 platinum loop from the slant-preserving slant.
The culture was performed by reciprocal shaking (amplitude 4 cm, 135 times / min) for 22 hours at 0 ° C. For the main culture, charge 3.0 ml of the main culture medium into a 10-volume jar amenta, and after sterilization, 500 ml.
Was inoculated into the preculture liquid of Temperature is 30 ° C, rotation speed is 300 rpm, aeration is 1 vvm, pH is 6.8 with 5N NaOH.
Controlled to ~ 7.0. As a defoamer, ADEKA NOL LG
109 (trade name of a product of Asahi Denka Co., Ltd.) was used. Approximately 8 hours after the start of culturing, before the stationary phase, the total sugar concentration was 10%, Na
Supplemental sugar solution 1.5 was added so that the content of ₄ Cl was 3%. As an analytical method, the bacterial cell concentration depends on the wet bacterial cell weight, the total sugar concentration depends on the Somogi-Nelson method after hydrochloric acid hydrolysis, and the L-lysine hydrochloride concentration indicates the bacterial cadaveris (Bacterium cadaveris). From L. lysine decarboxylase from E. coli. The final results are collectively shown in Table 4.

Example 3 An example of using molasses obtained by subjecting a raw molasses produced in Filipin to electrodialysis as a raw material for L-lysine fermentation is shown.

Preparation of treated molasses Raw molasses 9 from Filipin adjusted to Brix 50 was treated with the same dialysis machine as used in Example 1. Operating conditions are cell voltage 2.0V, average current density 2.69Amp / d
m ² , flow rate 70 / hr, electrodialysis time 6 hours. The concentrated molasses after electrodialysis was used as the treated molasses.

Table 5 collectively shows the analytical values of the treated molasses produced in Filipin and the untreated molasses. (However, it is displayed according to the total sugar concentration of molasses produced from Okibatsu.) Fermentation test The strains, medium and culture method used were the same as in Example 2. The time-dependent changes in L-lysine hydrochloride concentration, bacterial cell concentration, and total sugar concentration are shown in FIG. 3 and the final results are shown in Table 6 collectively.

Claims (1)

[Claims] 1. A raw molasses is electrodialyzed using an electrodialyzer having a multi-chamber structure in which a plurality of cation-exchange membranes and neutral membranes are alternately combined, and the total ash content in the raw molasses is about 1/2 to. A method for producing a molasses product for fermentation, which comprises reducing the concentration within a range of about 1/4.