JPS6140391B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a bacterial powder in which bacteria are less likely to die during drying and storage by using a dispersion medium containing corn staple liquor. When manufacturing bacterial powder of lactic acid bacteria or Bifidobacterium bacteria, it is common practice to first suspend the bacterial cells collected from the culture medium in an aqueous solution (dispersion medium) of a protective substance and then dry and powder them. It is known that the protective substances used have a large effect on the drying yield and storage stability of bacteria. Protective substances used in the production of lactic acid bacteria or Bifidobacterium powder include glucose, lactose, sucrose, malic acid, aspartic acid, lysine,
Saccharides such as glutamic acid, arginine, sorbitol xylitol, etc., polyalcohols, amino acids, organic acids, etc. have strong hydrogen bonds, and have certain molecular shapes such as OH groups and NH ₂ groups arranged on the 6-carbon ring. A low-molecular compound with a size of
Albumin, gelatin, soluble starch, alginic acid, yeast extract, carboxymethylcellulose,
These include serum, high-molecular compounds such as skim milk powder, and natural mixtures. These protective substances are low-molecular compounds that have strong hydrogen bonds, so they stabilize bacterial cell components instead of water during drying, and high-molecular compounds or natural mixtures cover the surface of cells and prevent damage to cell membranes. It is thought that this is due to the prevention of
Furthermore, if a low-molecular compound and a high-molecular compound or a natural mixture are used together, the killing of bacteria can be further reduced. However, since these substances are generally expensive, it is not practical to use them in large quantities, and it is currently not possible to obtain bacterial powder containing a large number of viable bacteria for a long period of time. It is. The present inventors conducted various studies on bacterial protective substances used in the production of lactic acid bacteria or Bifidobacterium bacterial powder, and as a result, they discovered that corn staple liquor had an excellent protective effect, and thus arrived at the present invention. did. The present invention will be described in detail below with reference to test examples. Test Example 1 Lactobacillus acidophilus (), Lactobacillus acidophilus (), Lactobacillus acidophilus (), Lactobacillus bulgaricus (), Lactobacillus casei (), Lactobacillus casei (), Lactobacillus brevis () were used as lactic acid bacteria, and Bifidobacterium was used as Bifidobacterium. Bacterium bifidum (),
The same Longum () was cultured in ILS medium 1 at 37°C for 20 hours, and immediately after culturing, bacterial cells were separated from the culture solution using a refrigerated centrifuge and collected. Divide the obtained bacterial cells into two equal parts, and add (a) skim milk powder 10.0% (same weight %), sodium glutamate 1.0%, vitamin C 0.5%, pH 7.0.
The mixture was homogeneously suspended in 30 ml of a dispersion medium and dried at -30° C. under a vacuum of 50 μHg for 8 hours to form a powder. (Control) (b) Corn staple liquor 2.0%, skim milk powder 10
%, Sodium Glutamate 1.0%, Vitamins
It was uniformly suspended in 30 ml of a dispersion medium containing 0.5% C and PH 7.0, and dried and powdered under the same conditions as above. (Present Invention) The survival rates of bacteria immediately after drying obtained by the above two methods are shown in Table 1. Lactic acid bacteria and Bifidobacterium tend to be killed by drying, but the method of the present invention using corn staple liquor has a tendency to be killed by drying, compared to the control method using conventional and most practical dispersion media. Although there are some differences depending on the type of bacteria, the survival rate of all types of bacteria is high and mortality is low.

【table】

[Table] Test Example 2 The dried products obtained by the methods of Test Example 1 (a) and (b) were mixed in dry starch so that the number of viable bacteria was 1.0 x 10 ⁹ /g, and then placed in a sealed container. The bacteria were stored at 37°C for lactic acid bacteria and at 30°C for bifidobacterium. Table 2 shows the results of measuring the number of viable bacteria during storage. The number of viable bacteria of lactic acid bacteria and Bifidobacterium tends to decrease as storage length increases, but after 6 months of storage using the method of the present invention using corn staple liquor,
Although there are differences depending on the bacterial species, the number of viable bacteria for all bacterial species is 10 ⁷ /
After 12 months of storage, 10 to 1000 times more viable bacteria remain than in the control method.

【table】

[Table] As described above, when corn staple liquor is added to a dispersion medium for producing bacterial powder, it exhibits an excellent effect in preventing killing of bacteria during drying and storage. In carrying out the method of the present invention, bacteria are cultured at 37°C using a suitable bacterial strain and medium for producing bacterial powder.
After about 30 hours, when the maximum number of bacteria is reached, the bacteria can be isolated and collected from the culture solution. Corn staple liquor added to the dispersion medium is 1% of the dispersion medium.
As mentioned above, preferably 2 to 3% is used, and when freeze-drying, if it exceeds 7%, the drying time tends to be longer. The bacterial cells are homogeneously suspended in a dispersion medium and then turned into a dry powder using either freeze-dried powder or spray drying. Store and use as is, or press into tablets with a tablet machine and store.
May be used. Incidentally, if the method of the present invention is carried out, the death of bacteria during drying and storage can be reduced, so that a bacterial powder containing a large number of viable bacteria and suitable for long-term storage can be obtained. Examples are shown below. Example 1 Lactobacillus acidophilus starter
It was inoculated into ILS medium 1 and cultured at 37°C for 20 hours.
After that, the culture solution was introduced into a refrigerated centrifuge and centrifuged at 10,000 g.
Bacterial cells were separated from the culture solution at 5° C. for 10 minutes and collected.
The obtained bacterial cells were uniformly suspended in 30 ml of a dispersion medium containing 2.0% corn staple liquor, 10.0% skim milk powder, 1.0% sodium glutamate, 1.0% vitamin C, and pH 7.0, and then frozen at -30°C. It was dried and powdered under the conditions of a drying shelf temperature of 30°C and a vacuum degree of 50 μHg. The obtained dry matter was 5.1g, and the average number of viable bacteria was 2.9×10 ¹¹ /g, with a survival rate of 96%.
It was hot. This dried product was mixed with 200 times the amount of dried starch, and stored in a sealed container for one year. The number of viable bacteria after storage was 2.0×10 ⁵ /g. Example 2 A starter of Bifidobacterium bifidum was inoculated into ILS medium 1 and cultured at 37°C for 20 hours.
After that, isolate the bacterial cells using the culture solution in the same manner as in Example 1.
Bacteria were collected. The obtained bacterial cells are mixed with cornstaple liquor.
The suspension was homogeneously suspended in 30 ml of a dispersion medium containing 3.0% protease decomposition product of skim milk powder, 5.0% sucrose, 1.0% arginine, and pH 7.0, and then dried and powdered in the same manner as in Example 1. The obtained dry matter was 5.2g, and the number of viable bacteria was 1.0.
×10 ¹¹ /g, survival rate was 90%. This dried product
After mixing in 200 times the amount of dry starch (viable bacteria count 1.8)
×10 ⁹ /g) was compressed into tablets using a tablet machine, and stored in a sealed container for one year. The number of viable bacteria after storage was 2.5×10 ⁷ /g.

Claims (1)

[Claims] 1. A bacterial powder characterized by culturing lactic acid bacteria or bifidobacteria, collecting the bacteria from the culture solution, suspending the bacteria in a dispersion medium containing corn staple liquor, and then drying and powdering the bacteria. manufacturing method.