JP2510902B2 - Method for producing yeast containing high iron concentration - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive and efficient method for producing yeast containing iron at a high concentration.

[0002]

2. Description of the Related Art In recent years, the deficiency of iron and calcium has been highlighted in Japan. Especially the problem of iron deficiency is serious in menstruating women and pregnant women. It is recognized that this is due to insufficient intake of iron itself and low intestinal absorption of dietary iron. And, the search for substances that help the absorption of iron is also quite ongoing.

For example, JP-A-54-157890 and JP-A-
No. 57-68783 is to obtain yeast cells containing a high concentration of iron by culturing by a conventional culturing method in a medium containing iron salts. That is, JP-A-54-157890 is characterized by culturing edible microorganisms capable of incorporating these substances in a medium containing water-soluble substances such as calcium and iron, and JP-A-57-157890. -68783 is
The present invention is characterized by culturing an edible microorganism capable of incorporating this substance in a medium containing a water-soluble substance of iron at a high concentration. However, these have low productivity and have a problem as an industrial production method.

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present inventor has developed a yeast cell that is transformed into an active and easily utilized form by incorporating iron, which is essential for maintaining human health, into yeast and undergoing its life activity. If it could be manufactured, it was considered that the bacterial cells could be used in medicines, foods and beverages. Then, when the conditions for the iron uptake by the yeast cells were examined, it was revealed that the yeast cells take up iron at a high concentration by selecting appropriate conditions.

[0005]

The present invention has been completed based on these findings, and a yeast is suspended in an aqueous solution containing a water-soluble salt of iron at a concentration high enough not to kill the yeast. It is a method for producing a yeast cell containing a large amount of iron, which is characterized by turbidity and stirring or shaking in a non-culture manner.

[0006] In the present specification, the term "non-cultured" refers to a condition under which there is substantially no chemical substance required for the growth of bacterial cells. By the way, as the prior art related to the present invention,
There are the above-mentioned JP-A-54-157890 and JP-A-57-68783, but in both cases, the dry yeast produced per 1 liter of the culture solution is as low as about 4 g. On the other hand, the present invention obtains bacterial cells containing iron at a high concentration of 1000 to 8000 ppm simply by suspending yeast in an aqueous solution containing only iron salt and shaking it under non-culturing conditions. That is, since it does not require a medium, it is low in cost, and since it is simply an aqueous solution of iron salt, washing after yeast cell collection can be performed in an extremely short time. Yeast over 20g is produced, and the productivity is very high.

Therefore, the present invention is completely different from the prior art. The iron salt used in the present invention may be any salt as long as it has appropriate water solubility, does not significantly inhibit the survival of yeast cells, and can be efficiently taken up by yeast cells. . In particular,
Ferrous sulfate, ferrous chloride, ferrous citrate, ferrous fumarate, and ferrous gluconate can be used alone or in combination.

[0008] The addition amount of iron salt is 50 to 50% as iron ion concentration because iron is relatively easy to cause growth inhibition of microorganisms.
It is preferable to limit it to 1500 ppm. As stirring conditions, the temperature is 4 to 40 ° C, preferably 20 to 25 ° C.
The stirring time is 1 to 72 hours and can be appropriately selected according to the amount of iron to be incorporated. Since the stirring is performed in a suspended state, a stirrer that can be uniformly stirred is used.

In the present invention, any yeast classified into yeast can be used, for example, bacteria belonging to the genus such as Tizosaccharomyces, Endomybsis, Hansenula, Saccharomyces, Candida, Pichia, so-called brewer's yeast and bread. Examples include those commonly referred to as yeast and sake yeast. As the liquid for suspending the yeast, it is inexpensive to use water, and tap water is usually sufficient.

The yeast cell concentration should be selected in consideration of efficient iron uptake, but, for example, 10 to 40%, particularly 10 to 20% is preferable as compressed yeast. The pH of the yeast suspension is preferably 5.0 to 8.0.

[0011]

INDUSTRIAL APPLICABILITY According to the present invention, yeast containing a high iron concentration can be produced in a non-cultured manner. Therefore, a medium, which was essential in the conventional method, is not required. Also, the washing of the yeast cells after collection can be extremely easily performed.

[0012]

EXAMPLES The present invention will now be described in detail with reference to examples, but these do not limit the present invention in any way. Example 1 5.6 g of ferrous sulfate was dissolved in 1000 ml of tap water, and 200 g of compressed brewer's yeast ( Saccharomyces cerevisiae) was added and suspended.
The mixture was stirred at 5 ° C for 16 hours so that the suspension became uniform. After completion of stirring, the suspension was collected by centrifugation. Iron attached to the cell wall was washed with 0.01 M hydrochloric acid, washed once with tap water, and then freeze-dried to obtain 18.5 g of dried yeast.
When the iron content was measured by atomic absorption spectrometry, it was 1850 pp
m of iron was taken in.

Further, the viable cells after washing and collecting the cells were crushed at 4 ° C. using glass beads and suspended in water, and the centrifugal supernatant was subjected to gel filtration using Sephadex G-75. However, iron was detected only in the polymer fraction. From this fact, it is presumed that the iron taken in is in the form of existence in which it is bound to macromolecules such as proteins. Example 2 1.4 g of ferrous sulfate was dissolved in 250 ml of tap water, 50 g of pressed brewer's yeast was added and suspended, and the mixture was stirred at 25 ° C. for 72 hours and then treated in the same manner as in Example 1 to give a dry weight of 5.6 g and iron. Content 8300ppm
Of dry yeast was obtained.

Example 3 Ferrous fumarate 20 mM was dissolved in 100 ml of tap water, 20 g of compressed brewer's yeast was added and suspended, and the mixture was stirred at 25 ° C. for 48 hours, and then the suspension was collected by centrifugation to collect tap water. , Twice with 0.01 M hydrochloric acid, once with water, then twice with acetone, and dried under reduced pressure to obtain 2.0 g of dried bacterial cells (iron content 3300 ppm).

Example 4 Ferrous oxalate (20 mM) was dissolved in tap water (100 ml), and pressed brewer's yeast (20 g) was added and suspended. The mixture was stirred at 25 ° C. for 48 hours and treated in the same manner as in Example 1 to give 4600 ppm of iron. 1.8 g of dry cells was obtained.

Claims (1)

(57) [Claims] 1. A method for producing a yeast having a high iron concentration, which comprises stirring the yeast in a suspension state in an aqueous solution containing an iron salt in a non-cultured manner.